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Business statistics
Quantitative techniques
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Decision making & Analysisin
Business Management
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DECISION MAKIN
• A metho! "o# !ete#mining o$timalst#ategies %hen "ace! %ith seve#al
!ecision alte#natives an! at times anunce#tain $atte#n o" "utu#e events
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Business & !ecision making
• Business management levels
• Basis o" !ecision
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'y$es o" Decision Making Situations
• (nce#tainty ) –
anything can ha$$en* %e !on+t kno% – Still some analysis is $ossi,le on !i-e#ent outcomes
. $ayo-s/ ,ase! on !i-e#ent a$$#oaches
– 'he !ecision make# is una,le o# un%illing toestimate $#o,a,ilities
– A$$ly a common sense c#ite#ion
0o# e1am$le – Senio# management !ecision making is St#ategic in
natu#e &long te#m – 2a#tici$ating in a com$etition
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'y$es o" Decision Making Situations
Decision making un!e# ce#tainty –
state o" natu#e is kno%n – !ecision is to choose the alte#native %ith the ,est $ayo-
– 3e kno%4assume %ell !e5ne! unchanging system
– Mathematical mo!els an! equations a#e !e#ive!
– 3e t#y to im$lement ,est system* mo!el
0o# e1am$le – 6o%e# management !ecision making involves
Im$lementation o" actiona,le o,7ectives an! $lans & issho#t te#m
– M82* E82* many so"t%a#e ,ase! systems* #igi! #ules an!#egulations
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'y$es o" Decision Making Situations
Decision making un!e# #isk .$#o,a,ility situations/
• E1$ecte! 9alue C#ite#ion
– com$ute e1$ecte! value "o# each !ecision alte#native
– select alte#native %ith :,est; e1$ecte! value
– %e kno% some $#o,a,ilities o" things to ha$$en
0o# E1am$le – Mi!!le management !ecision making involves conve#sion
o" st#ategies into actiona,le o,7ectives an! $lans & isme!ium te#m
– 3he#eve# some $#o,a,ility o" ha$$ening o" event can ,ecalculate! O# some $atte#n can ,e o,se#ve! #ega#!ing
ha$$ening o" events In such cases many time 2#o,a,ilitiesa#e calculate! using $ast !ata
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(nce#tainty vs #isk vsce#tainty
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• Al%ays management st#uggles toconve#t unce#tain to #isk* an! #isk toce#tainty
•
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• 3hole %o#l! o# any %o#l! o$e#atesun!e# ce#tain la%s an! in>uences
– I" one un!e#stan! these la%s* one canmanage ,ette#
– I" one has to "#ee onesel" "#om one la%one has to take hel$ o" anothe# la%
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• I" one is not a,le to kno% an! un!e#stan!la%s o" ho% things ha$$en ? like cause &e-ect* then one look "o# $#o,a,ilistic
outcomes ,ase! on $ast !ata * t#ying to 5n!$atte#ns
• I" one is not a,le to get $ast !ata an!
$#o,a,ility associate!* one goes "o# the$ossi,le choices ,ase! on outcomes .$ayo-s/an! ones o$timistic* $essimistic a$$#oach
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• Kno%ing 4 in"o#mation #e!ucesunce#tainty an! #isks
• 'hat+s %he#e %hole o" ,usiness statisticsan! o$e#ations #esea#ch $lays a #ole
• 3hich is "u#the# !evelo$e! as Businessanalytics
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• In to!ay+s scena#io* %hole o" ,usinessmanagement is to someho% a$$#oachto%a#!s #ight !ecision %ith mo#e an!
mo#e ce#tainty
• But %ith highly changing an! !ynamic
envi#onment an! com$etition mo#ean! mo#e unce#tainty is the#e
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• 2#o,lem is com$oun!e! %hen lo%e#management ten!s to ,ecomest#ategic an! senio# management
ten!s to ,ecome highly #igi! an!!e5ne! . at times to savethemselves "#om !i@cult4ha#sh
lea!e#shi$ !ecisions/ o# at times%himsical
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• 8esulting into .o# #esulte! "#om /"ailu#e o" e1isting mo!els an!systems
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Some a$$#oaches
• Analysis ,ase! !ete#ministic Mo!els likeinvento#y mo!els* $#o!uction $lanning mo!els*m#$ mo!els* 6inea# $#og#amming mo!els
• Ma#ket #esea#ch* quality* s$c* sqc* ,ase! onsam$ling an! $#o,a,ility
• Simulation
• (n!e# unce#tainty ? o$timistic* conse#vative*minima1 #eg#et* game theo#y
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Business statistics
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• Business Statistics is a scienceassisting you to make businessdecisions under
uncertainties ,ase! on somenume#ical an! measu#a,le scalesDecision making $#ocesses must ,e
,ase! on !ata* not on $e#sonalo$inion no# on ,elie"
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Decisions,Decisions,
Decisions,
BUSINESS IS ALL ABOUT
Decisions
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Business Decisions
(nce#tainties
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UNCERTAINITIES
'
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• Just like weater! i" you cannotcontrol someting! you souldlearn ow to measure and
analy#e it! in order to $redict it!e%ecti&ely
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Its allabout'ATA!
IN()R*ATI)N
AN''ECISI)N!dear+
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'he 'he
elementselements
a#e the entities on %hich !ata a#ea#e the entities on %hich !ata a#e
collecte!collecte!
AA va#ia,leva#ia,le is a cha#acte#istic o" inte#est "o# the eleis a cha#acte#istic o" inte#est "o# the ele
'he set o" measu#ements collecte! "o# a $a#ticula# 'he set o" measu#ements collecte! "o# a $a#ticula#
element is calle! anelement is calle! an o,se#vationo,se#vation
'he total num,e# o" !ata values in a !ata set is the 'he total num,e# o" !ata values in a !ata set is the num,e# o" elements multi$lie! ,y the num,e# o" num,e# o" elements multi$lie! ,y the num,e# o" va#ia,lesva#ia,les
Elements* 9a#ia,les* an! O,se#vationsElements* 9a#ia,les* an! O,se#vations
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Stock Annual Ea#n4Stock Annual Ea#n4
E1change Sales.M/ Sha#e./E1change Sales.M/ Sha#e./
Data* Data Sets*Data* Data Sets*Elements* 9a#ia,les* an! O,se#vationsElements* 9a#ia,les* an! O,se#vations
Com$anyCom$any
Data#amData#am
Ene#gySouthEne#gySouth
KeystoneKeystone
6an!Ca#e6an!Ca#e 2sycheme!ics2sycheme!ics
AMEAME F F FGH FGH
O'CO'C FF FF H H
NJSENJSE HFHF FGHFGH
NJSENJSE FF F F AMEAME HF HF F F
9a#ia,les9a#ia,les
ElementElement NamesNames
Data SetData Set
O,se#vationO,se#vation
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Measu#ing DA'A
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Scales o" Measu#ement
'he scale in!icates the !ata summa#iLation an! 'he scale in!icates the !ata summa#iLation an! statistical analyses that a#e most a$$#o$#iatestatistical analyses that a#e most a$$#o$#iate 'he scale in!icates the !ata summa#iLation an! 'he scale in!icates the !ata summa#iLation an! statistical analyses that a#e most a$$#o$#iatestatistical analyses that a#e most a$$#o$#iate
'he scale !ete#mines the amount o" in"o#mation 'he scale !ete#mines the amount o" in"o#mation containe! in the !atacontaine! in the !ata
'he scale !ete#mines the amount o" in"o#mation 'he scale !ete#mines the amount o" in"o#mation containe! in the !atacontaine! in the !ata
Scales o" measu#ement inclu!eScales o" measu#ement inclu!eScales o" measu#ement inclu!eScales o" measu#ement inclu!eNominalNominal
O#!inalO#!inal
Inte#valInte#val
8atio8atio
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Scales o" Measu#ement• Nominal
AA nonnume#ic la,elnonnume#ic la,el o#o# nume#ic co!enume#ic co!e may ,e use!may ,e use!AA nonnume#ic la,elnonnume#ic la,el o#o# nume#ic co!enume#ic co!e may ,e use!may ,e use!
Data a#eData a#e la,els o# namesla,els o# names use! to i!enti"y anuse! to i!enti"y an att#i,ute o" the elementatt#i,ute o" the element
Data a#eData a#e la,els o# namesla,els o# names use! to i!enti"y anuse! to i!enti"y an att#i,ute o" the elementatt#i,ute o" the element
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E1am$leE1am$le Stu!ents o" a unive#sity a#e classi5e! ,y theStu!ents o" a unive#sity a#e classi5e! ,y the school in %hich they a#e en#olle! using aschool in %hich they a#e en#olle! using a
nonnume#ic la,el such as Business*
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Scales o" Measu#ement• O#!inal
AA nonnume#ic la,elnonnume#ic la,el o#o# nume#ic co!enume#ic co!e may ,e use!may ,e use!AA nonnume#ic la,elnonnume#ic la,el o#o# nume#ic co!enume#ic co!e may ,e use!may ,e use!
'he !ata have the $#o$e#ties o" nominal !ata an! 'he !ata have the $#o$e#ties o" nominal !ata an! thethe o#!e# o# #ank o" the !ata is meaning"ulo#!e# o# #ank o" the !ata is meaning"ul
'he !ata have the $#o$e#ties o" nominal !ata an! 'he !ata have the $#o$e#ties o" nominal !ata an! thethe o#!e# o# #ank o" the !ata is meaning"ulo#!e# o# #ank o" the !ata is meaning"ul
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Scales o" Measu#ement
• Inte#val
Inte#val !ata a#eInte#val !ata a#e al%ays nume#ical%ays nume#icInte#val !ata a#eInte#val !ata a#e al%ays nume#ical%ays nume#ic
'he !ata have the $#o$e#ties o" o#!inal !ata* an! 'he !ata have the $#o$e#ties o" o#!inal !ata* an!
the inte#val ,et%een o,se#vations is e1$#esse! inthe inte#val ,et%een o,se#vations is e1$#esse! in te#ms o" a 51e! unit o" measu#ete#ms o" a 51e! unit o" measu#e
'he !ata have the $#o$e#ties o" o#!inal !ata* an! 'he !ata have the $#o$e#ties o" o#!inal !ata* an!
the inte#val ,et%een o,se#vations is e1$#esse! inthe inte#val ,et%een o,se#vations is e1$#esse! in te#ms o" a 51e! unit o" measu#ete#ms o" a 51e! unit o" measu#e
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Scales o" Measu#ement
• Inte#val
E1am$leE1am$le Melissa has an SA' sco#e o"Melissa has an SA' sco#e o" FF* %hile Kevin* %hile Kevin
has an SA' sco#e o"has an SA' sco#e o" FPFFPF Melissa sco#e! Melissa sco#e! $oints mo#e than Kevin$oints mo#e than Kevin
E1am$leE1am$le Melissa has an SA' sco#e o"Melissa has an SA' sco#e o" FF* %hile Kevin* %hile Kevin
has an SA' sco#e o"has an SA' sco#e o" FPFFPF Melissa sco#e! Melissa sco#e! $oints mo#e than Kevin$oints mo#e than Kevin
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Scales o" Measu#ement• 8atio
'he !ata have all the $#o$e#ties o" inte#val !ata 'he !ata have all the $#o$e#ties o" inte#val !ata an! thean! the #atio o" t%o values is meaning"ul#atio o" t%o values is meaning"ul
'he !ata have all the $#o$e#ties o" inte#val !ata 'he !ata have all the $#o$e#ties o" inte#val !ata an! thean! the #atio o" t%o values is meaning"ul#atio o" t%o values is meaning"ul
9a#ia,les such as !istance* height* %eight* an! tim9a#ia,les such as !istance* height* %eight* an! tim use the #atio scaleuse the #atio scale 9a#ia,les such as !istance* height* %eight* an! tim9a#ia,les such as !istance* height* %eight* an! tim use the #atio scaleuse the #atio scale
'his 'his scale must contain a Le#o valuescale must contain a Le#o value that in!icatesthat in!icates
that nothing e1ists "o# the va#ia,le at the Le#o $ointhat nothing e1ists "o# the va#ia,le at the Le#o $oin
'his 'his scale must contain a Le#o valuescale must contain a Le#o value that in!icatesthat in!icates
that nothing e1ists "o# the va#ia,le at the Le#o $ointhat nothing e1ists "o# the va#ia,le at the Le#o $oin
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Scales o" Measu#ement• 8atio
E1am$leE1am$le Melissa+s college #eco#! sho%sMelissa+s college #eco#! sho%s HH c#e!it hou#sc#e!it hou#s ea#ne!* %hile Kevin+s #eco#! sho%sea#ne!* %hile Kevin+s #eco#! sho%s c#e!itc#e!it
hou#s ea#ne! Kevin has t%ice as many c#e!ithou#s ea#ne! Kevin has t%ice as many c#e!it hou#s ea#ne! as Melissahou#s ea#ne! as Melissa
E1am$leE1am$le Melissa+s college #eco#! sho%sMelissa+s college #eco#! sho%s HH c#e!it hou#sc#e!it hou#s ea#ne!* %hile Kevin+s #eco#! sho%sea#ne!* %hile Kevin+s #eco#! sho%s c#e!itc#e!it
hou#s ea#ne! Kevin has t%ice as many c#e!ithou#s ea#ne! Kevin has t%ice as many c#e!it hou#s ea#ne! as Melissahou#s ea#ne! as Melissa
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B(SINESSS'A'IS'ICS
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Al%ays 8emem,e# itsall a,out DA'A
An! %e %ant to take!ecision ,ase! on ou#
collection an!inte#$#etation o" !ata
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'y$es o" Data
Data
Numerical
(Quantitative)
Categorical
(Qualitative)
Discrete Continuous
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Qualitative Data
6a,els o# names6a,els o# names use! to i!enti"y an att#i,ute o" eachuse! to i!enti"y an att#i,ute o" each elementelement 6a,els o# names6a,els o# names use! to i!enti"y an att#i,ute o" eachuse! to i!enti"y an att#i,ute o" each elementelement
O"ten #e"e##e! to asO"ten #e"e##e! to as catego#ical !atacatego#ical !ataO"ten #e"e##e! to asO"ten #e"e##e! to as catego#ical !atacatego#ical !ata
(se eithe# the nominal o# o#!inal scale o" (se eithe# the nominal o# o#!inal scale o" measu#ementmeasu#ement (se eithe# the nominal o# o#!inal scale o" (se eithe# the nominal o# o#!inal scale o" measu#ementmeasu#ement
Can ,e eithe# nume#ic o# nonnume#icCan ,e eithe# nume#ic o# nonnume#icCan ,e eithe# nume#ic o# nonnume#icCan ,e eithe# nume#ic o# nonnume#ic
A$$#o$#iateA$$#o$#iate statistical analysesstatistical analyses a#e #athe#a#e #athe# limite!limite!A$$#o$#iateA$$#o$#iate statistical analysesstatistical analyses a#e #athe#a#e #athe# limite!limite!
i i
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Quantitative DataQuantitative Data
Quantitative !ata a#eQuantitative !ata a#e al%ays nume#ical%ays nume#icQuantitative !ata a#eQuantitative !ata a#e al%ays nume#ical%ays nume#ic
O#!ina#y a#ithmetic o$e#ations a#e meaning"ul "o#O#!ina#y a#ithmetic o$e#ations a#e meaning"ul "o#
quantitative !ataquantitative !ata
O#!ina#y a#ithmetic o$e#ations a#e meaning"ul "o#O#!ina#y a#ithmetic o$e#ations a#e meaning"ul "o#
quantitative !ataquantitative !ata
Q i i
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Quantitative DataQuantitative Data
Quantitative !ata in!icateQuantitative !ata in!icate ho% many o# ho% muchho% many o# ho% muchQuantitative !ata in!icateQuantitative !ata in!icate ho% many o# ho% muchho% many o# ho% much discretediscrete!! i" measu#ing ho% manyi" measu#ing ho% manydiscretediscrete!! i" measu#ing ho% manyi" measu#ing ho% many
continuouscontinuous!! i" measu#ing ho% muchi" measu#ing ho% muchcontinuouscontinuous!! i" measu#ing ho% muchi" measu#ing ho% much
i iQ i i D
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Quantitative DataQuantitative Data
Quantitative !ata in!icateQuantitative !ata in!icate ho% many o# ho% muchho% many o# ho% muchQuantitative !ata in!icateQuantitative !ata in!icate ho% many o# ho% muchho% many o# ho% much discretediscrete!! i" measu#ing ho% manyi" measu#ing ho% manydiscretediscrete!! i" measu#ing ho% manyi" measu#ing ho% many
continuouscontinuous!! i" measu#ing ho% muchi" measu#ing ho% muchcontinuouscontinuous!! i" measu#ing ho% muchi" measu#ing ho% much
I9E EAM26ES O0 BO'<
Cl i" i bl di t
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Te time it ta!es to "rive to #or!$
Te num%er o& cre"it car"s a 'erson as$
Te num%er o& em'loees #or!ing in a large "e'artment
store$
Te num%er o& cars stolen eac #ee! in a large cit$
Classi"y eac &ariable as discrete orcontinuous+
S l " M tS l " M t
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Scales o" Measu#ementScales o" Measu#ement
QualitativeQualitativeQualitativeQualitative QuantitativQuantitativeeQuantitativQuantitativee
Nume#icalNume#icalNume#icalNume#ical Nume#icalNume#icalNume#icalNume#icalNon)Non)nume#icalnume#icalNon)Non)nume#icalnume#ical
DataDataDataData
NominaNominallNominaNominall O#!inaO#!inallO#!inaO#!inall NominalNominalNominalNominal O#!inalO#!inalO#!inalO#!inal Inte#valInte#valInte#valInte#val 8atio8atio8atio8atio
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For each of the following variables, determine whether the
variable is categorical or numerical.
If the variable is numerical, determine whether the variable
is discrete or continuous.
a$ Num%er o& tele'ones 'er ouseol"
%$ Lengt (in minutes) o& te longest long"istance call
made per month
c+ ,eter someone in te ouseold owns acell $one
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I66 NO3 3E
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I66 NO3 3E
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Data
Sources
*rimar Secon"ar
E+'eriment *u%lise"
(, OnLine)Surve O%servation
Data Sou#ces
C S ti l D tC#oss Sectional Data
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C#oss)Sectional DataC#oss)Sectional Data
C#oss)sectional !ataC#oss)sectional !ata a#e collecte! at the same o#a#e collecte! at the same o# a$$#o1imately the same $oint in timea$$#o1imately the same $oint in time
C#oss)sectional !ataC#oss)sectional !ata a#e collecte! at the same o#a#e collecte! at the same o# a$$#o1imately the same $oint in timea$$#o1imately the same $oint in time
E1am$leE1am$le !ata !etailing the num,e# o" ,uil!ing !ata !etailing the num,e# o" ,uil!ing $e#mits issue! in une FF in each o" the counties$e#mits issue! in une FF in each o" the counties o" Ohioo" Ohio
E1am$leE1am$le !ata !etailing the num,e# o" ,uil!ing !ata !etailing the num,e# o" ,uil!ing $e#mits issue! in une FF in each o" the counties$e#mits issue! in une FF in each o" the counties o" Ohioo" Ohio
'ime Se#ies Data'ime Se#ies Data
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'ime Se#ies Data 'ime Se#ies Data
'ime se#ies !ata 'ime se#ies !ata a#e collecte! ove# seve#al timea#e collecte! ove# seve#al time $e#io!s$e#io!s 'ime se#ies !ata 'ime se#ies !ata a#e collecte! ove# seve#al timea#e collecte! ove# seve#al time $e#io!s$e#io!s
E1am$leE1am$le !ata !etailing the num,e# o" ,uil!ing !ata !etailing the num,e# o" ,uil!ing $e#mits issue! in 6ucas County* Ohio in each o" $e#mits issue! in 6ucas County* Ohio in each o" the last H monthsthe last H months
E1am$leE1am$le !ata !etailing the num,e# o" ,uil!ing !ata !etailing the num,e# o" ,uil!ing $e#mits issue! in 6ucas County* Ohio in each o" $e#mits issue! in 6ucas County* Ohio in each o" the last H monthsthe last H months
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3E CAN
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Key De5nitions
• A $o$ulation .unive#se/ is the
collection o" things un!e#
consi!e#ation
• A sam$le is a $o#tion o" the $o$ulation
selecte! "o# analysis
• A $a#amete# is a summa#y measu#e
com$ute! to !esc#i,e a cha#acte#istic
o" the $o$ulation
• A statistic is a summa#y measu#e
com ute! to !esc#i,e a cha#acte#istic
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2o$ulation an! Sam$le
-o$ulation Sam$le
(se $a#amete#s to
summa#iLe "eatu#es
(se statistics tosumma#iLe "eatu#es
In"e#ence on the $o$ulation "#om the sam$
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Statistical Metho!s
Statistical-eto"s
Descri'tive
Statistics
In&erential
Statistics
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Desc#i$tive Statistics
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Desc#i$tive Statistics
• Desc#i$tive statistics a#e theta,ula#* g#a$hical* an! nume#icalmetho!s use! to summa#iLe !ata
Descri'tive Statistics9Descri'tive Statistics9
Tese are statisticalTese are statistical
meto"s use" tometo"s use" to"escri%e "ata tat"escri%e "ata tat
ave %een collecte"$ave %een collecte"$
Desc#i$tive Statistics
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Desc#i$tive Statistics 'a,ula# an! #a$hical
2#esentations• Summa#iLing Qualitative Data• Summa#iLing Quantitative Data
'y$es o" Data 'y$es o" Data 'y$es o" Data
Data
Numerical(Quantitative)
Categorical(Qualitative)
Discrete Continuous
Data
Numerical(Quantitative)
Categorical(Qualitative)
Discrete Continuous
E1am$le Ma#a!a Inn
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E1am$le Ma#a!a Inn
uests staying at Ma#a!a Inn %e#e
aske! to #ate the quality o" thei#accommo!ations as ,eing excellent *above average* average* below
average* o# poor 'he #atings $#ovi!e!,y a sam$le o" F guests a#e
Belo% Ave#ageBelo% Ave#age
A,ove Ave#ageA,ove Ave#age
A,ove Ave#ageA,ove Ave#age
Ave#ageAve#age
A,ove Ave#ageA,ove Ave#age
Ave#ageAve#age
A,ove Ave#ageA,ove Ave#age
Ave#ageAve#ageA,ove Ave#ageA,ove Ave#age
Belo% Ave#ageBelo% Ave#age
2oo#2oo#
E1cellentE1cellent
A,ove Ave#ageA,ove Ave#age
Ave#ageAve#age
A,ove Ave#ageA,ove Ave#age A,ove Ave#ageA,ove Ave#age
Belo% Ave#ageBelo% Ave#age
2oo#2oo#
A,ove Ave#ageA,ove Ave#age
Ave#ageAve#age
0#equency Dist#i,ution0#equency Dist#i,ution
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0#equency Dist#i,ution0#equency Dist#i,ution
2oo#2oo#
Belo% Ave#ageBelo% Ave#age
Ave#ageAve#ageA,ove Ave#ageA,ove Ave#age
E1cellentE1cellent
PP
'otal 'otal F F
8ating8ating 0#equency0#equency
8elative 0#equency an!8elative 0#equency an!
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8elative 0#equency an!q y2e#cent 0#equency Dist#i,utions2e#cent 0#equency Dist#i,utions
2oo#2oo#
Belo% Ave#ageBelo% Ave#age
Ave#ageAve#age
A,ove Ave#ageA,ove Ave#age
E1cellentE1cellent
FF
FF
'otal 'otal FF FF
FF
FFFF
8elative8elative
0#equency0#equency
2e#cent2e#cent
0#equency0#equency8ating8ating
F.FF/ F.FF/ FF
4F 4F FF
Ba# #a$hBa# #a$h
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2oo# Belo%Ave#age
Ave#age A,oveAve#age
E1cellent
( r e .
u en c y
Rating
Ba# #a$hBa# #a$h
H
G
P
FMa#a!a Inn Quality 8atingsMa#a!a Inn Quality 8atings
2ie Cha#t2ie Cha#t
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Belo%Ave#age R
Ave#age
R
A,oveAve#age R
2oo#FR
E1cellent R
Ma#a!a InnMa#a!a Inn QualityQuality
8atings8atings
Ma#a!a InnMa#a!a Inn QualityQuality
8atings8atings
2ie Cha#t2ie Cha#t
0#equency Dist#i,ution0#equency Dist#i,ution
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AA "#equency !ist#i,ution"#equency !ist#i,ution is a ta,ula# summa#y o" is a ta,ula# summa#y o" !ata sho%ing the "#equency .o# num,e#/ o" items!ata sho%ing the "#equency .o# num,e#/ o" items in each o" seve#al non)ove#la$$ing classesin each o" seve#al non)ove#la$$ing classes
AA "#equency !ist#i,ution"#equency !ist#i,ution is a ta,ula# summa#y o" is a ta,ula# summa#y o" !ata sho%ing the "#equency .o# num,e#/ o" items!ata sho%ing the "#equency .o# num,e#/ o" items in each o" seve#al non)ove#la$$ing classesin each o" seve#al non)ove#la$$ing classes
'he o,7ective is to 'he o,7ective is to $#ovi!e insights$#ovi!e insights a,out the !ataa,out the !ata that cannot ,e quickly o,taine! ,y looking only atthat cannot ,e quickly o,taine! ,y looking only at the o#iginal !atathe o#iginal !ata
'he o,7ective is to 'he o,7ective is to $#ovi!e insights$#ovi!e insights a,out the !ataa,out the !ata that cannot ,e quickly o,taine! ,y looking only atthat cannot ,e quickly o,taine! ,y looking only at the o#iginal !atathe o#iginal !ata
0#equency Dist#i,ution0#equency Dist#i,ution
8elative 0#equency Dist#i,ution8elative 0#equency Dist#i,ution
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'he 'he #elative "#equency#elative "#equency o" a class is the "#action o#o" a class is the "#action o# $#o$o#tion o" the total num,e# o" !ata items$#o$o#tion o" the total num,e# o" !ata items ,elonging to the class,elonging to the class
'he 'he #elative "#equency#elative "#equency o" a class is the "#action o#o" a class is the "#action o# $#o$o#tion o" the total num,e# o" !ata items$#o$o#tion o" the total num,e# o" !ata items ,elonging to the class,elonging to the class
AA #elative "#equency !ist#i,ution#elative "#equency !ist#i,ution is a ta,ula#is a ta,ula# summa#y o" a set o" !ata sho%ing the #elativesumma#y o" a set o" !ata sho%ing the #elative "#equency "o# each class"#equency "o# each class
AA #elative "#equency !ist#i,ution#elative "#equency !ist#i,ution is a ta,ula#is a ta,ula# summa#y o" a set o" !ata sho%ing the #elativesumma#y o" a set o" !ata sho%ing the #elative "#equency "o# each class"#equency "o# each class
8elative 0#equency Dist#i,ution8elative 0#equency Dist#i,ution
e#cen #equency
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e#cen #equencyDist#i,ution
'he 'he $e#cent "#equency$e#cent "#equency o" a class is the #elativeo" a class is the #elative "#equency multi$lie! ,y FF"#equency multi$lie! ,y FF 'he 'he $e#cent "#equency$e#cent "#equency o" a class is the #elativeo" a class is the #elative "#equency multi$lie! ,y FF"#equency multi$lie! ,y FF
AA $e#cent "#equency !ist#i,ution$e#cent "#equency !ist#i,ution is a ta,ula#is a ta,ula#
summa#y o" a set o" !ata sho%ing the $e#centsumma#y o" a set o" !ata sho%ing the $e#cent "#equency "o# each class"#equency "o# each class
AA $e#cent "#equency !ist#i,ution$e#cent "#equency !ist#i,ution is a ta,ula#is a ta,ula#
summa#y o" a set o" !ata sho%ing the $e#centsumma#y o" a set o" !ata sho%ing the $e#cent "#equency "o# each class"#equency "o# each class
Ba# #a$h
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Ba# #a$h
AA ,a# g#a$h,a# g#a$h is a g#a$hical !evice "o# $#esentingis a g#a$hical !evice "o# $#esenting
qualitative !ataqualitative !ata On one a1is .usually the ho#iLontal a1is/* %e s$eci"yOn one a1is .usually the ho#iLontal a1is/* %e s$eci"y the la,els that a#e use! "o# each o" the classesthe la,els that a#e use! "o# each o" the classes
AA "#equency"#equency** #elative "#equency#elative "#equency* o#* o# $e#cent "#equency$e#cent "#equency
scale can ,e use! "o# the othe# a1is .usually thescale can ,e use! "o# the othe# a1is .usually the ve#tical a1is/ve#tical a1is/
'he 'he ,a#s a#e se$a#ate!,a#s a#e se$a#ate! to em$hasiLe the "act that eato em$hasiLe the "act that ea class is a se$a#ate catego#yclass is a se$a#ate catego#y
2ie Cha#t
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2ie Cha#t
'he 'he $ie cha#t$ie cha#t is a commonly use! g#a$hical !eviceis a commonly use! g#a$hical !evice
"o# $#esenting"o# $#esenting #elative "#equency !ist#i,utions "o##elative "#equency !ist#i,utions "o# qualitative !ataqualitative !ata
Since the#e a#e HF !eg#ees in a ci#cle*Since the#e a#e HF !eg#ees in a ci#cle*
a class %ith a #elative "#equency o"a class %ith a #elative "#equency o" %oul!%oul! consumeconsume .HF/ PF.HF/ PF !eg#ees o" the ci#cle!eg#ees o" the ci#cle
E1am$leE1am$le Ma#a!a InnMa#a!a Inn
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Insights aine! "#om the 2#ece!ing 2ie Cha#tInsights aine! "#om the 2#ece!ing 2ie Cha#t
E1am$leE1am$le Ma#a!a Inn Ma#a!a Inn
One)hal" o" the custome#s su#veye! gave Ma#a!One)hal" o" the custome#s su#veye! gave Ma#a! a quality #ating o" :a,ove ave#age; o# :e1cellena quality #ating o" :a,ove ave#age; o# :e1cellen .looking at the le"t si!e o" the $ie/ 'his might.looking at the le"t si!e o" the $ie/ 'his might $lease the manage#$lease the manage#
0o#0o# eacheach custome# %ho gave an :e1cellent; #aticustome# %ho gave an :e1cellent; #ati the#e %e#ethe#e %e#e t%ot%o custome#s %ho gave a :$oo#;custome#s %ho gave a :$oo#; #ating .looking at the to$ o" the $ie/ 'his shoul#ating .looking at the to$ o" the $ie/ 'his shoul !is$lease the manage#!is$lease the manage#
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A categorical variable has three categories with
the following frequencies of occurrence:
a$ Com'ute te 'ercentage o& values in eac categor$
%$ Construct a %ar cart$
c$ Construct a 'ie cart$
"$ Construct a *areto "iagram
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• Jou manage a team that sells com$ute#ha#!%a#e to so"t%a#e !evelo$ment com$aniesAt each com$any* you# #e$#esentatives have a$#ima#y contact Jou have catego#iLe! these
contacts ,y the !e$a#tment o" the com$any in%hich they %o#k .Development * ComputerServices* Finance* Other * Don't Know/
• .contactssav/
• (se 0#equencies to stu!y the !ist#i,ution o"!e$a#tments to see i" it meshes %ith you#goals
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• $#o!uces a "#equency ta,le an! $iecha#t "o# the va#ia,le dept
• 3hatUs the inte#$#etation=
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• At a glance* you see that the$lu#ality o" you# contacts %o#k in thecom$ute# se#vices !e$a#tments o"
thei# #es$ective com$anies* "ollo%e!,y those in the 5nancial an!!evelo$ment !e$a#tments
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Business Statistics
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2A8E'O 28INCI26E
• 'he -areto $rinci$le e/ists wente ma0ority o" items in a set o"data occur in a small num,e# o"
catego#ies an! the "e% #emainingitems a#e s$#ea! out ove# a la#genum,e# o" catego#ies 'hese t%o
g#ou$s a#e o"ten #e"e##e! to as thevital "e% an! the t#ivial many
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'he 2a#eto Diag#am
• In a -areto diagram! tecategori#ed res$onses are $lottedin descending order! according to
thei# "#equencies* an! a#e com,ine!%ith a cumulative $e#centage line onthe same cha#t
• 'he 2a#eto !iag#am can i!enti"ysituations in %hich the 2a#eto $#inci$leoccu#s
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• 'he 2a#eto !iag#am has the a,ility tose$a#ate the vital "e% "#om the t#ivialmany* ena,ling you to "ocus on theim$o#tant catego#ies
• In situations in %hich the !ata involve!consist o" !e"ective o# noncon"o#ming
items* the 2a#eto !iag#am is a $o%e#"ultool "o# $#io#itiLing im$#ovement e-o#ts
V
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V
• 3e have !ata "o# a la#ge in7ection)mol!ingcom$any that manu"actu#es $lasticmol!e! Com$onents use! in com$ute#key,oa#!s* %ashing machines*automo,iles* an! television sets
• 'he !ata $#esente! in 'a,le consist o" all
com$ute# key,oa#!s %ith !e"ects$#o!uce! !u#ing a th#ee)month $e#io!
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Using (re.uencies to Study
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Using (re.uencies to Study)rdinal 'ata
• In a!!ition to the !e$a#tment o" eachcontact* you have #eco#!e! thei#com$any #anks (se 0#equencies to
stu!y the !ist#i,ution o" com$any#anks to see i" it meshes %ith you#goals
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• 'he "#equency ta,le "o# o#!inal !atase#ves much the same $u#$ose asthe ta,le "o# nominal !ata 0o#
e1am$le* you can see "#om the ta,lethat R o" you# contacts a#e
7unio# manage#s
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•
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represent the root causes of pharmac errors at a hospital during a
recent time period:
2eason &or :ailure :re;uenc Additional instructions !"
#ose $%
#rug !&
#uplicate order entr $$
Frequenc &'(mission $!
(rder not discontinued when received !$
(rder not received )$
*atient )
+oute &
(ther
a$ Construct a *areto "iagram$
%$ Discuss te vital &e# an" trivial man reasons &or the root causes
of pharmac errors.
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Summa#iLing QuantitativeData
umma# L ng uan a veData
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gData
• 0#equency Dist#i,ution
• 8elative 0#equency an! 2e#cent0#equency Dist#i,utions
• Dot 2lot
•
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8e$ai# 'he manage# o"
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Sam$le o" 2a#ts Cost "o# F 'une)u$sSam$le o" 2a#ts Cost "o# F 'une)u$s
P E C G P D K C C K K N P P G F P C H N
C E H P C N G P H H C K C P C K C N C H
E F I C I H N H G P C E F K C C H K G F E F P
G K P C G G H G G D H G C E H P H C C IH N G N P G E F E C P E F K C P H P H N C D
P E C G P D K C C K K N P P G F P C H N
C E H P C N G P H H C K C P C K C N C H
E F I C I H N H G P C E F K C C H K G F E F P
G K P C G G H G G D H G C E H P H C C I
H N G N P G E F E C P E F K C P H P H N C D
0#equency Dist#i,ution 'a,le
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• ) Dete#mine #ange• ) Select num,e# o" classes
- Usually ,et%een an! F inclusive
• ) Com$ute class inte#vals .%i!th/
• ) Dete#mine class ,oun!a#ies .limits/
• ) Com$ute class mi!$oints
• H) Count o,se#vations & assign toclasses
Ste$s
0#equency Dist#i,ution
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q y
• ui!elines "o# Selecting Num,e# o"
Classes (se ,et%een(se ,et%een an!an! FF classesclasses Data sets %ith a la#ge# num,e# o" elementsData sets %ith a la#ge# num,e# o" elements usually #equi#e a la#ge# num,e# o" classesusually #equi#e a la#ge# num,e# o" classes
Smalle# !ata sets usually #equi#e "e%e# classesSmalle# !ata sets usually #equi#e "e%e# classes
0#equency Dist#i,ution
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q y.Continue!/• ui!elines "o# Selecting 3i!th o"
Classes
L a r g e s t D a t a V a l u e S m a l l e s t D a t a V a l u e
N u m b e r o f C l a s s e s
−
(se classes o" equal %i!th(se classes o" equal %i!thA$$#o1imate Class 3i!th A$$#o1imate Class 3i!th
E1am$ e 0#equencyDist#i,ution
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Dist#i,ution
0o#
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q yDist#i,utions
F)PF)P
HF)HPHF)HPF)PF)P
GF)GPGF)GP
PF)PPPF)PP
FF)FPFF)FP
2a#ts2a#ts
Cost ./Cost ./
FF
HH
FF
'otal FF 'otal FF
8elative8elative
0#equency0#equency
HH
FF
FFFF
2e#cent2e#cent
0#equency0#equency
4F4F F.FFF.FF//
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Anothe# common g#a$hical $#esentation o" Anothe# common g#a$hical $#esentation o"
quantitative !ataquantitative !ata is ais a histog#amhistog#am 'he va#ia,le o" inte#est is $lace! on the ho#iLontal 'he va#ia,le o" inte#est is $lace! on the ho#iLontal a1isa1is
A #ectangle is !#a%n a,ove each class inte#val %ithA #ectangle is !#a%n a,ove each class inte#val %ith
its height co##es$on!ing to the inte#val+sits height co##es$on!ing to the inte#val+s "#equenc"#equenc #elative "#equency#elative "#equency* o#* o# $e#cent "#equency$e#cent "#equency
(nlike a ,a# g#a$h* a histog#am has(nlike a ,a# g#a$h* a histog#am has no naturalno natural separation between rectanglesse paration between rectangles o" a!7acent classeso" a!7acent classes
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• Symmet#ic
- 6e"t tail is the mi##o# image o" the #ighttail
- E1am$le heights an! %eights o" $eo$le
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• Mo!e#ately Ske%e! 6e"t
- A longe# tail to the le"t
- E1am$le e1am sco#es
8 el at i v e0 # e q
u en c y F
F
F
F
F
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• Mo!e#ately 8ight Ske%e! - A 6onge# tail to the #ight
- E1am$le housing values
8 el at i v e0 # e q u en c y F
F
F
F
F
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•
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Cumulative "#equency !ist#i,utionCumulative "#equency !ist#i,ution −− sho%s thesho%s the num,e# o" items %ith values less than o# equal tonum,e# o" items %ith values less than o# equal to the u$$e# limit o" each classthe u$$e# limit o" each class
Cumulative "#equency !ist#i,utionCumulative "#equency !ist#i,ution −− sho%s thesho%s the num,e# o" items %ith values less than o# equal tonum,e# o" items %ith values less than o# equal to the u$$e# limit o" each classthe u$$e# limit o" each class
CumulativeCumulative
#elative#elative
"#equency !ist#i,ution"#equency !ist#i,ution
? sho%s? sho%s
the $#o$o#tion o" items %ith values less than o#the $#o$o#tion o" items %ith values less than o# equal to the u$$e# limit o" each classequal to the u$$e# limit o" each class
CumulativeCumulative #elative#elative "#equency !ist#i,ution"#equency !ist#i,ution ? sho%s? sho%s the $#o$o#tion o" items %ith values less than o#the $#o$o#tion o" items %ith values less than o# equal to the u$$e# limit o" each classequal to the u$$e# limit o" each class
CumulativeCumulative $e#cent$e#cent "#equency !ist#i,ution"#equency !ist#i,ution ? sho%s? sho%s
the $e#centage o" items %ith values less than o#the $e#centage o" items %ith values less than o# equal to the u$$e# limit o" each classequal to the u$$e# limit o" each class
CumulativeCumulative $e#cent$e#cent "#equency !ist#i,ution"#equency !ist#i,ution ? sho%s? sho%s
the $e#centage o" items %ith values less than o#the $e#centage o" items %ith values less than o# equal to the u$$e# limit o" each classequal to the u$$e# limit o" each class
Cumulative Dist#i,utions
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• E/am$le4
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AnAn ogiveogive is a g#a$h o" ais a g#a$h o" a cumulativecumulative
!ist#i,ution!ist#i,ution 'he !ata values a#e sho%n on the ho#iLontal 'he !ata values a#e sho%n on the ho#iLontala1isa1is Sho%n on the ve#tical a1is a#e theSho%n on the ve#tical a1is a#e the
cumulative "#equencies* o#cumulative "#equencies* o#
cumulative #elative "#equencies* o#cumulative #elative "#equencies* o#
cumulative $e#cent "#equenciescumulative $e#cent "#equencies
'he "#equency . 'he "#equency .one o" the a,oveone o" the a,ove/ o" each class/ o" each classis $lotte! as a $ointis $lotte! as a $oint
'he $lotte! $oints a#e connecte! ,y st#aight 'he $lotte! $oints a#e connecte! ,y st#aightlineslines
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Ogive %ithOgive %ith
C l ti 2 t 0 iCumulative 2e#cent 0#equencies
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2a#ts2a#tsCost ./Cost ./
F
F
HF
GF
FF C um ul at i v
e2 e# c ent 0 # e
q u en c y
C um ul at i v
e2 e# c ent 0 # e
q u en c y
F HF F GF PF FF FF HF F GF PF FF F
.GP* H/.GP* H/
Cumulative 2e#cent 0#equenciesCumulative 2e#cent 0#equencies
'une)u$ 2a#ts Cost 'une)u$ 2a#ts Cost 'une)u$ 2a#ts Cost 'une)u$ 2a#ts Cost
State! an! '#ue .o# 8eal/ Class 6imits
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'#ue Classes '#ue Classes A#e those classes such that theA#e those classes such that theu$$e# t#ue limit o" a class is the same as the lo%e#u$$e# t#ue limit o" a class is the same as the lo%e#t#ue limit o" the ne1t classt#ue limit o" the ne1t class 0o# com$a#ison* the state! class limits an! t#ue0o# com$a#ison* the state! class limits an! t#ueclass limits a#e given in the "ollo%ing ta,leYne1tclass limits a#e given in the "ollo%ing ta,leYne1tsli!esli!e
. /
State! an! '#ue .o# 8eal/ Class 6imits
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State!State! '#ue '#ueHFF)PPHFF)PP PPF u$ to ,ut not inclu!ingPPF u$ to ,ut not inclu!ingPPFPPFGFF)PPPGFF)PPP PPF u$ to ,ut not inclu!ingPPF u$ to ,ut not inclu!ing
PPPFPPPF
In the 5#st column o" the a,ove ta,le the !ata %e#eIn the 5#st column o" the a,ove ta,le the !ata %e#e#oun!e! to the nea#est !olla# 0o# e1am$le*#oun!e! to the nea#est !olla# 0o# e1am$le* PPFPPF
%as #oun!e! u$ to%as #oun!e! u$ to
GFFGFF
an! taile! in the secon!an! taile! in the secon!
class Any amount ove#class Any amount ove# PPPP ,ut un!e#,ut un!e# PPFPPF %as%as#oun!e! !o%n to#oun!e! !o%n to PPPP an! inclu!e! in the 5#st classan! inclu!e! in the 5#st class
'hus* the 'hus* the HFF)PPHFF)PP class actually inclu!es all !ataclass actually inclu!es all !ata"#om"#om PPFPPF inclusive u$ to ,ut not inclu!inginclusive u$ to ,ut not inclu!ing
PPFPPF
. /
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Dot 2lot
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• One o" the sim$lest g#a$hicalsumma#ies o" !ata is a !ot $lot
• A ho#iLontal a1is sho%s the #angeo" !ata values
• 'hen each !ata value is#e$#esente! ,y a !ot $lace! a,ovethe a1is
Dot 2lot
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FF HFHF FF GFGF PFPF FFFF
Cost ./
'une)u$ 2a#ts Cost 'une)u$ 2a#ts Cost
+ + + +++++ ++++++++++ ++ + ++ + + +
++ ++ + + ++ ++ ++ ++ ++ +
Stem an! 6ea" !iag#am
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Stem an! 6ea" !iag#am
• A stem;and;lea" dis$layorgani#es data into grou$s1called stems3 so tat te &alues
witin each g#ou$ .the leaves/,#anch out to the #ight on each #o%
'he #esulting !is$lay allo%s you to
see ho% the !ata a#e !ist#i,ute! an!%he#e concent#ations o" !ata e1ist
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• su$$ose that stu!ents "#om you#class eat lunch at a "ast)"oo!#estau#ant 'he "ollo%ing !ata a#e
the amounts s$ent "o# lunch
• F* F* GF* F* F* GF*
HF* GF* PF* PF* F* F*PF* HF* HHF
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• 'o "o#m the stem)an!)lea" !is$lay*you use the units as the stems an!#oun! the !ecimals
• .the leaves/ to one !ecimal $lace• 0o# e1am$le* the 5#st value is F
Its stem .#o%/ is * an! its lea" is
• 'he secon! value* is F Its stem.#o%/ is * an! its lea" is
V
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C8OSS 'AB(6A'IONS
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C8OSS 'AB(6A'IONS
• 'he stu!y o" $atte#ns that may e1ist,et%een t%o o# mo#e catego#icalva#ia,les is common in ,usiness
'hese $atte#ns a#e e1$laine! ,yc#oss)ta,ulating the !ata
• Jou can $#esent crosstabulations
in tabular "orm 1contingencytables3 or gra$ical "orm
'he Contingency 'a,le
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'he Contingency 'a,le
• A contingency table $resents teresults o" two categorical&ariables+ Te 0oint res$onses
areclassi5e! so that the catego#ies o"one va#ia,le a#e locate! in the #o%san! the catego#ies o" the othe# va#ia,lea#e locate! in the columns 'he values
locate! at the inte#sections o" the #o%san! columns a#e calle! cells+
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• 'e$ending on te ty$e o"contingency table constructed!te cells "or each #o% column
com,ination contain the "#equency*the $e#centage o" the ove#all total*the $e#centage o" the #o% total* o#
the $e#centage o" the column total
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• Mutual"un!s 1ls• C#oss ta,ulation o" catego#y vs
o,7ective
• C#oss ta,ulation o" o,7ective vs #isk
'he Scatte# 2lot
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'he Scatte# 2lot
• Jou use a scatter $lot to e/amine$ossible relationsi$s betweentwo numerical &ariables
• 0o# each o,se#vation* you $lot oneva#ia,le on the X ais and the other
variable on the vertical ! ais
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• the cost o" a "ast)"oo! ham,u#ge#meal an! the cost o" t%o movietickets in F cities a#oun! the %o#l!
• 'he !ata 5le Cost o" 6iving1lscontains the com$lete !ata set
• a+ Construct si/ se$arate scatter $lots+(or eac! use te ove#all cost in!e1 as the !
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(or eac! use te ove#all cost in!e1 as the !ais" Use the monthly rent "o# a t%o),e!#oom
a$a#tment* the costs o" a cu$ o" co-ee %ithse#vice* a "ast)"oo! ham,u#ge# meal* !#ycleaning a men s ,laLe#* tooth$aste* an! movietickets as the X ais"
• b+ ,at conclusions can you reac aboutte relationsi$ o" the ove#all cost in!e1 tothese si1 va#ia,les=
Statistical Metho!s
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Statistical-eto"s
Descri'tive
Statistics
In&erential
Statistics
Desc#i$tive Statistics
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• Desc#i$tive statistics a#e the
ta,ula#* g#a$hical* an! nume#icalmetho!s use! to summa#iLe !ata
Descri'tive Statistics9Descri'tive Statistics9
Tese are statisticalTese are statistical
meto"s use" tometo"s use" to"escri%e "ata tat"escri%e "ata tat
ave %een collecte"$ave %een collecte"$
Desc#i$tive Statistics
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Nume#ical Measu#es
• Measu#es o" 6ocation• Measu#es o" 9a#ia,ility
Measu#es o" 6ocation
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I" the measu#es a#e com$ute!I" the measu#es a#e com$ute! "o# !ata "#om a sam$le*"o# !ata "#om a sam$le*they a#e calle!they a#e calle! sam$le statisticssam$le statistics
I" the measu#es a#e com$ute!I" the measu#es a#e com$ute!
"o# !ata "#om a $o$ulation*"o# !ata "#om a $o$ulation*they a#e calle!they a#e calle! $o$ulation $a#amete#$o$ulation $a#amete#
A sam$le statistic is #e"e##e! toA sam$le statistic is #e"e##e! to
as theas the $oint estimato#$oint estimato# o" theo" theco##es$on!ing $o$ulation $a#amete#co##es$on!ing $o$ulation $a#amete#0o# e1am$le*0o# e1am$le* thethe sam$le mean is asam$le mean is a$oint estimato# o" the $o$ulation mean$oint estimato# o" the $o$ulation mean
MeanMean
Me!ianMe!ian Mo!eMo!e
2e#centiles2e#centiles
Qua#tilesQua#tiles
Mean
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• 'he mean o" a !ata set is the
ave#age o" all the !ata values• As %e sai!* the sam$le mean is
the $oint estimato# o" the
$o$ulation mean µ
Sam$le MeanSam$le Mean
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Num,e# o" Num,e# o" o,se#vationso,se#vations
in the sam$lein the sam$le
Num,e# o" Num,e# o" o,se#vationso,se#vations
in the sam$lein the sam$le
Sum o" the valuesSum o" the valueso" theo" the nn o,se#vationso,se#vationsSum o" the valuesSum o" the valueso" theo" the nn o,se#vationso,se#vations
i
n
=∑
2o$ulation Mean2o$ulation Mean µ µ
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Num,e# o" Num,e# o" o,se#vations ino,se#vations in
the $o$ulationthe $o$ulation
Num,e# o" Num,e# o" o,se#vations ino,se#vations in
the $o$ulationthe $o$ulation
Sum o" the valuesSum o" the valueso" theo" the ## o,se#vationso,se#vationsSum o" the valuesSum o" the valueso" theo" the ## o,se#vationso,se#vations
i
#
µ =∑
Sam$le MeanSam$le Mean
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Seventy e@ciency a$a#tmentsSeventy e@ciency a$a#tments%e#e #an!omly sam$le! in%e#e #an!omly sam$le! in
a small college to%n 'hea small college to%n 'he
monthly #ent $#ices "o#monthly #ent $#ices "o#
these a$a#tments a#e liste!these a$a#tments a#e liste!
in ascen!ing o#!e# on the ne1t sli!ein ascen!ing o#!e# on the ne1t sli!e
E/am$le4E/am$le4 A$a#tment 8ents A$a#tment 8ents
Sam$le MeanSam$le MeanE1am$le Continue!E1am$le Continue!
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I N K I D F I D F I D K I D K I D K I D K I D K I I F I I F
I I F I I F I I F I I K I I K I I K I I K I I K I K F I K F
I K F I K F I K F I K F I K F I H F I H F I H F I H K I H K
I H K I C F I C F I C N I C K I C K I C K I G F I G F I G F
I G F I G K I P F I P F I P F K F F K F F K F F K F F K E F
K E F K E K K N K K N K K N K K D K K I P K K F K C F K C F
K C K K C K K G F K P F H F F H F F H F F H F F H E K H E K
I N K I D F I D F I D K I D K I D K I D K I D K I I F I I F
I I F I I F I I F I I K I I K I I K I I K I I K I K F I K F
I K F I K F I K F I K F I K F I H F I H F I H F I H K I H K
I H K I C F I C F I C N I C K I C K I C K I G F I G F I G F
I G F I G K I P F I P F I P F K F F K F F K F F K F F K E F
K E F K E K K N K K N K K N K K D K K I P K K F K C F K C F
K C K K C K K G F K P F H F F H F F H F F H F F H E K H E K
*ontly Rent "or :
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D I * D K H I P F & G F
C F
i
n
= = =∑
I N K I D F I D F I D K I D K I D K I D K I D K I I F I I F
I I F I I F I I F I I K I I K I I K I I K I I K I K F I K F
I K F I K F I K F I K F I K F I H F I H F I H F I H K I H K
I H K I C F I C F I C N I C K I C K I C K I G F I G F I G F
I G F I G K I P F I P F I P F K F F K F F K F F K F F K E F
K E F K E K K N K K N K K N K K D K K I P K K F K C F K C F
K C K K C K K G F K P F H F F H F F H F F H F F H E K H E K
I N K I D F I D F I D K I D K I D K I D K I D K I I F I I F
I I F I I F I I F I I K I I K I I K I I K I I K I K F I K F
I K F I K F I K F I K F I K F I H F I H F I H F I H K I H K
I H K I C F I C F I C N I C K I C K I C K I G F I G F I G F
I G F I G K I P F I P F I P F K F F K F F K F F K F F K E F
K E F K E K K N K K N K K N K K D K K I P K K F K C F K C F
K C K K C K K G F K P F H F F H F F H F F H F F H E K H E K
*ontly Rent "or :
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Data
i" a#e the mi!)values an!
a#e the co##es$on!ing
"#equencies* %he#e the su,sc#i$t Z$ +stan!s "o# the num,e# o" classes*then the mean is
∑∑= iii
f z f z
k z z z z .,,.........,, 321
k f f f f ,........,,, 321
eomet#ic Mean
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eomet#ic mean is !e5ne! as the $ositive #oot o" the$#o!uct o" o,se#vations Sym,olically*
It is also o"ten use! "o# a set o" num,e#s %hose valuesa#e meant to ,e multi$lie! togethe# o# a#e e1$onentialin natu#e* such as !ata on the g#o%th o" the human
$o$ulation o# inte#est #ates o" a 5nancial investment
0in! geomet#ic mean o" #ate o" g#o%th * * * **
n
n x x x xG
/1
321 )(
=
3eighte! Mean
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3eighte! Mean
'he 3eighte! mean o" the $ositive #eal
num,e#s 1E*1N* * 1n %ith thei# %eight %E*%N*
* %n is !e5ne! to ,e
∑
∑
=
=
= n
i
i
n
i
ii
w
xw
x
1
1
2otential 2#o,lem %ithMeans
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Means
Sam$le mean gives equal %eight to allmeasu#ements
Outliers can have a la#ge in>uence on
the com$ute! mean valueDisto#ts ou# intuition a,out the central
tendency o" the measu#e! values
2otential 2#o,lem %ithMeans
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Means
Mean
Mean
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Me!ianMe!ian
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PP HH GG
0o# an0o# an o!! num,e#o!! num,e# o" o,se#vationso" o,se#vations
in ascen!ing o#!e#in ascen!ing o#!e#
HH GG PP o,se#vations o,se#vations
the me!ian is the mi!!le valuethe me!ian is the mi!!le value
Me!ian PMe!ian P
Me!ianMe!ian
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PP HH GG
0o# an0o# an even num,e#even num,e# o" o,se#vationso" o,se#vations
in ascen!ing o#!e#in ascen!ing o#!e#
HH GG FF G o,se#vationsG o,se#vations
the me!ian is the ave#age o" the mi!!le t%o valuesthe me!ian is the ave#age o" the mi!!le t%o values
Me!ian .P X H/4 Me!ian .P X H/4
PP
FF
Me!ian E1am$le
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I N K I D F I D F I D K I D K I D K I D K I D K I I F I I F
I I F I I F I I F I I K I I K I I K I I K I I K I K F I K F
I K F I K F I K F I K F I K F I H F I H F I H F I H K I H K
I H K I C F I C F I C N I C K I C K I C K I G F I G F I G F
I G F I G K I P F I P F I P F K F F K F F K F F K F F K E F
K E F K E K K N K K N K K N K K D K K I P K K F K C F K C F
K C K K C K K G F K P F H F F H F F H F F H F F H E K H E K
I N K I D F I D F I D K I D K I D K I D K I D K I I F I I F
I I F I I F I I F I I K I I K I I K I I K I I K I K F I K F
I K F I K F I K F I K F I K F I H F I H F I H F I H K I H K
I H K I C F I C F I C N I C K I C K I C K I G F I G F I G F
I G F I G K I P F I P F I P F K F F K F F K F F K F F K E F
K E F K E K K N K K N K K N K K D K K I P K K F K C F K C F
K C K K C K K G F K P F H F F H F F H F F H F F H E K H E K
Ave#aging the th an! Hth !ata valuesAve#aging the th an! Hth !ata values
Me!ian . X /4 Me!ian . X /4
*ontly Rent "or :
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6F 6o%e# class ,oun!a#y o" the me!ianclass
h 3i!th o" the me!ian class
" F 0#equency o" the me!ian class
0 Cumulative "#equency o" the $#e)me!ian class
−+= F n
f
h L M
o
oe2
E1am$le)0in! Me!ian
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E1am$le)0in! Me!ian
Age in ears umber of births /umulative number ofbirths
!&.)0!1.) "'' "''
!1.)0$&.) !12 $))
$&.)0$1.) !'%' &%%$
$1.)0%&.) !2&2 )%"$
%&.)0%1.) $1& )")"
%1.)0&&.) 1! )'&'&&.)0&1.) !" )'"%
All ages )'"% 0
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Mo!e
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'he 'he mo!emo!e o" a !ata set is the value that occu#s %ito" a !ata set is the value that occu#s %it
greatest %re&uency greatest %re&uency 'he g#eatest "#equency can occu# at t%o o# mo#e 'he g#eatest "#equency can occu# at t%o o# mo#e !i-e#ent values!i-e#ent values
I" the !ata have e1actly t%o mo!es* the !ata a#eI" the !ata have e1actly t%o mo!es* the !ata a#e
,imo!al,imo!al I" the !ata have mo#e than t%o mo!es* the !ata a#I" the !ata have mo#e than t%o mo!es* the !ata a# multimo!almultimo!al
Mo!e E1am$le
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INK IDF IDF IDK IDK IDK IDK IDK IIF IIF
IIF IIF IIF IIK IIK IIK IIK IIK IKF IKF
IKF IKF IKF IKF IKF IHF IHF IHF IHK IHK
IHK ICF ICF ICN ICK ICK ICK IGF IGF IGF
IGF IGK IPF IPF IPF KFF KFF KFF KFF KEF
KEF KEK KNK KNK KNK KDK KIP KKF KCF KCF
KCK KCK KGF KPF HFF HFF HFF HFF HEK HEK
INK IDF IDF IDK IDK IDK IDK IDK IIF IIF
IIF IIF IIF IIK IIK IIK IIK IIK IKF IKF
IKF IKF IKF IKF IKF IHF IHF IHF IHK IHK
IHK ICF ICF ICN ICK ICK ICK IGF IGF IGF
IGF IGK IPF IPF IPF KFF KFF KFF KFF KEF
KEF KEK KNK KNK KNK KDK KIP KKF KCF KCF
KCK KCK KGF KPF HFF HFF HFF HFF HEK HEK
F occu##e! most "#equently . times/F occu##e! most "#equently . times/
Mo!e FMo!e F
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No Mo!e
8a% Data F P GP H One Mo!e8a% Data HF PHF GP H P
P
Mo#e 'han Mo!e8a% Data G G
(se E1cel to Com$ute(se E1cel to Com$utethe Mean* Me!ian* an! Mo!ethe Mean* Me!ian* an! Mo!e
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o" the 0ollo%ing Data an! E1$lain theo" the 0ollo%ing Data an! E1$lain theAns%e#sAns%e#s
I N K I D F I D F I D K I D K I D K I D K I D K I I F I I F
I I F I I F I I F I I K I I K I I K I I K I I K I K F I K F
I K F I K F I K F I K F I K F I H F I H F I H F I H K I H K
I H K I C F I C F I C N I C K I C K I C K I G F I G F I G F
I G F I G K I P F I P F I P F K F F K F F K F F K F F K E F
K E F K E K K N K K N K K N K K D K K I P K K F K C F K C F
K C K K C K K G F K P F H F F H F F H F F H F F H E K H E K
I N K I D F I D F I D K I D K I D K I D K I D K I I F I I F
I I F I I F I I F I I K I I K I I K I I K I I K I K F I K F
I K F I K F I K F I K F I K F I H F I H F I H F I H K I H K
I H K I C F I C F I C N I C K I C K I C K I G F I G F I G F
I G F I G K I P F I P F I P F K F F K F F K F F K F F K E F
K E F K E K K N K K N K K N K K D K K I P K K F K C F K C F
K C K K C K K G F K P F H F F H F F H F F H F F H E K H E K
Mean* Me!ian* o# Mo!e=
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MeanI" the sum o" all values is meaning"ul
Inco#$o#ates all availa,le in"o#mation
Me!ianIntuitive sense o" cent#al ten!ency %ith
outlie#s
3hat is :ty$ical; o" a set o" values=
Mo!e3hen !ata can ,e g#ou$e! into !istinct
ty$es* catego#ies .categorical data/
3hich mean to use=
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Mean value must still con"o#m tocha#acte#istics o" a good $e#"o#mancemet#ic
6inea#
8elia,le8e$eata,le
Easy to use
Consistent
In!e$en!entBest measu#e o" $e#"o#mance still is
eecution time
2e#centiles
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A $e#centileA $e#centile $#ovi!es in"o#mation a,out ho% the$#ovi!es in"o#mation a,out ho% the
!ata a#e s$#ea! ove# the inte#val!ata a#e s$#ea! ove# the inte#val "#om the smalles"#om the smalles value to the la#gest valuevalue to the la#gest value
A!mission test sco#es "o# colleges an! unive#sitiesA!mission test sco#es "o# colleges an! unive#sities a#e "#equently #e$o#te! in te#ms o" $e#centilesa#e "#equently #e$o#te! in te#ms o" $e#centiles
Jou a#e "amilia# %ith Jou a#e "amilia# %ith $e#centile$e#centile sco#e o" nationalsco#e o" nationale!ucational tests such as MA'* an! SA'* %hiche!ucational tests such as MA'* an! SA'* %hich telltellyou %he#e you stan! in com$a#ison %ith othe#syou %he#e you stan! in com$a#ison %ith othe#s
0o# e1am$le* i" you a#e in the Gth $e#centile*0o# e1am$le* i" you a#e in the Gth $e#centile*
then GR o" the test)take#s sco#e! ,elo% you an!then GR o" the test)take#s sco#e! ,elo% you an!you a#e in the to$ R o" the test take#syou a#e in the to$ R o" the test take#s
'h th til " ! t t i
e#cent esDe5nition
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• 'he pth $e#centile o" a !ata set is a
value such that at least p $e#cent o"the items take on this value o# less an! at least .FF ) p/ $e#cent o" the
items take on this value o# mo#e
Ste$s "o# 0in!ing 2e#centilesSte$s "o# 0in!ing 2e#centiles
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A##ange the !ata in ascen!ing o#!e#A##ange the !ata in ascen!ing o#!e#
Com$ute in!e1Com$ute in!e1 ii* the* the $osition$osition o" theo" the p pthth $e#centile$e#centile
ii . . p p4FF/4FF/nn
I" I" ii is notis not an intege#*an intege#* #oun! u$#oun! u$ 'he 'he p p thth $e#centile$e#centile is the value in theis the value in the ii thth $osition$osition
I"I" ii is an intege#* theis an intege#* the p p thth $e#centile is the ave#age$e#centile is the ave#age
o" the values in $ositionso" the values in $ositions ii an!an! ii XX
GFth 2e#centile E1am$le
ii ..p4FF/4FF/n .GF4FF/F H.GF4FF/F H
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ii . . p p4FF/4FF/nn .GF4FF/F H .GF4FF/F H
Ave#aging the HAve#aging the Hthth
an! an! thth
!ata values!ata valuesGFth 2e#centile . X P/4 GFth 2e#centile . X P/4
Note Data is in ascen!ing o#!e#Note Data is in ascen!ing o#!e#
INK IDF IDF IDK IDK IDK IDK IDK IIF IIF
IIF IIF IIF IIK IIK IIK IIK IIK IKF IKF
IKF IKF IKF IKF IKF IHF IHF IHF IHK IHKIHK ICF ICF ICN ICK ICK ICK IGF IGF IGF
IGF IGK IPF IPF IPF KFF KFF KFF KFF KEF
KEF KEK KNK KNK KNK KDK KIP KKF KCF KCF
KCK KCK KGF KPF HFF HFF HFF HFF HEK HEK
GFGFthth 2e#centile2e#centile E1am$le Continue!E1am$le Continue!
::At least GFRAt least GFR ::At least FRAt least FR
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At least GFRAt least GFR o" the itemso" the items
take on a valuetake on a value o" o# less;o" o# less;
At least FRAt least FR o" the itemso" the items
take on a valuetake on a value o" o# mo#e;o" o# mo#e;
H4F G o# GFRH4F G o# GFR 4F o# FR4F o# FR
INK IDF IDF IDK IDK IDK IDK IDK IIF IIFIIF IIF IIF IIK IIK IIK IIK IIK IKF IKF
IKF IKF IKF IKF IKF IHF IHF IHF IHK IHK
IHK ICF ICF ICN ICK ICK ICK IGF IGF IGF
IGF IGK IPF IPF IPF KFF KFF KFF KFF KEF
KEF KEK KNK KNK KNK KDK KIP KKF KCF KCF
KCK KCK KGF KPF HFF HFF HFF HFF HEK HEK
(se E1cel to 0in! GF(se E1cel to 0in! GFthth 2e#centile2e#centile
E l 0 l 3 k h tE l 0 l 3 k h t GFGFthth til$e#centile
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A B C D E
7
A'art
ment
-ontl
2ent (
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E1cel 9alue 3o#ksheetE1cel 9alue 3o#ksheet
A B C D E
7
A'art
ment
-ontl
2ent (
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E1cel 0o#mula 3o#ksheetE1cel 0o#mula 3o#ksheet
'hi#! Qua#tile 'hi#! Qua#tile
!! iltil
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A B C D E
7
A'art
ment
-ontl
2ent (
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E1cel 9alue 3o#ksheetE1cel 9alue 3o#ksheet
A B C D E
7
A'art
ment
-ontl
2ent (
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At $resent only about = > o" atlas com$uterdo not make it to warranty $eriod+Currently Su$$lier ? su$$lies ci$ 1maincom$onent o" com$uter3+
Two su$$liers o" ci$ are tere ? @ +
Consultant said to take a sam$le o" 6< ci$s"rom eac sam$le and com$are te mean
li"e+
Results are a&erage li"e o" ? ci$s is 6<years and a&erage li"e o" ci$s is 5< years+Consultant orders to sto$ su$$ly "rom ? and
A"te# s%itching to su$$lie# J
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A"te# s%itching to su$$lie# J
mo#e then FR o" com$ute#ssta#te! "ailing ,e"o#e %a##anty$e#io!
3hat ha$$ene!=
Su$$lie# chi$s* n F
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F* F* F* F* P* * F* * P* F
Mean F yea#s* #ange yea#s*an! stan!a#! !eviation FH yea#s
Su$$lie# J chi$s* nF .li"e in yea#s/F* * * * F* * P* * G* Mean F yea#s* #ange G yea#s*an! stan!a#! !eviation FF yea#s
Te Ne# ?or! Cit Transit Autorit as @ust 'urcase" a %ran"
ne# t'e o& &luorescent ligt %ul%$
T % l% li& & 6 7= it t " "
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Tese %ul%s ave an average li&e o& 6$7= ears #it a stan"ar"
"eviation o& =$==$
Consultant &or te Transit Autorit, recommen"s tat on one
Satur"a evening %et#een mi"nigt an" 6 a$m$, #en te num%er
o& ri"ers is small, all te %ul%s in te su%#a sstem soul" %e
re'lace"$
A #or!er &or te sstem suggest re'lacing 68 o& te %ul%s eac
Satur"a evening &or te ne+t t#ent #ee!s until all te %ul%s are
re'lace"$
Consultant insists tat it is cea'er an" more e&&icient to re'lace allte %ul%s at once$ Te Transit Autorit listens to Consultant$
Set A * * * *
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Set B * * * *Set C * * * *
All th#ee sets have ave#age o"
Although all sets a#e !i-e#ent3e nee! measu#es %hich account "o#such !is$e#sion o" !ata
'he %o#! !is$e#sion is use! to !enote the
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!eg#ee o" hete#ogeneity in the !ata
It is an im$o#tant cha#acte#istic in!icatingthe e1tent to %hich o,se#vations va#y
amongst themselves
A measu#e o" !is$e#sion is !esigne! to statenume#ically the e1tent to %hich in!ivi!ual
o,se#vations va#y on the ave#age
easu#es o a# a y.Dis$e#sion/ It i "t ! i ,l t i! "It is o"ten !esi#a,le to consi!e# measu#es o" i ,ia#ia,il
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It is o"ten !esi#a,le to consi!e# measu#es o"It is o"ten !esi#a,le to consi!e# measu#es o" va#ia,iva#ia,il
.!is$e#sion/*.!is$e#sion/* as %ell as measu#es o" locationas %ell as measu#es o" location 0o# e1am$le* in choosing su$$lie#0o# e1am$le* in choosing su$$lie# AA o# su$$lie#o# su$$lie# BB %% might consi!e# not only themight consi!e# not only the average delivery ti average delivery ti each* ,ut also theeach* ,ut also the variability in delivery timevariability in delivery time "o"o
easu#es o a# a ty.Dis$e#sion/ 8ange8ange
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8ange8ange
Inte#qua#tile 8ange o#Inte#qua#tile 8ange o#Mi!s$#ea!Mi!s$#ea! 9a#iance9a#iance
Stan!a#! DeviationStan!a#! Deviation
Coe@cient o" 9a#iationCoe@cient o" 9a#iation
8ange
'he'he #ange#a
nge o" a !ata set is the !i-e#ence ,et%een to" a !ata set is the !i-e#ence ,et%een
th
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'he 'he #ange#ange o" a !ata set is the !i-e#ence ,et%een to" a !ata set is the !i-e#ence ,et%een th la#gest an! smallest !ata valuesla#gest an! smallest !ata values
It is theIt is the sim$lest measu#esim$lest measu#e o" va#ia,ilityo" va#ia,ility
It isIt is ve#y sensitiveve#y sensitive to the smallest an! la#gest !atato the smallest an! la#gest !ata valuesvalues
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n e#qua# e ange o# Mi!s$#ea! 'he'he inte#qua#tile #angeinte#
qua#tile #ange o" a !ata set is the !i-e#eno" a !ata set is the !i-e#en
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'he 'he inte#qua#tile #angeinte#qua#tile #ange o" a !ata set is the !i-e#eno" a !ata set is the !i-e#en ,et%een the,et%een the third quartilethird quartile an! thean! the frst quartil frst quartil
It is the #ange "o# theIt is the #ange "o# the mi!!le FRmi!!le FR o" the !atao" the !ata It ove#comes the sensitivity to e1t#eme !ata valueIt ove#comes the sensitivity to e1t#eme !ata value not e-ecte! ,y the e1t#eme valuesnot e-ecte! ,y the e1t#eme values
I n t e r ; u a r t i l e 2 a n g e = Q Q5 7
n e#qua# e angeE1am$le
#! Qua#tile .#! Qua#tile .++/ /
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INK IDF IDF IDK IDK IDK IDK IDK IIF IIF
IIF IIF IIF IIK IIK IIK IIK IIK IKF IKF
IKF IKF IKF IKF IKF IHF IHF IHF IHK IHK
IHK ICF ICF ICN ICK ICK ICK IGF IGF IGF
IGF IGK IPF IPF IPF KFF KFF KFF KFF KEF
KEF KEK KNK KNK KNK KDK KIP KKF KCF KCF
KCK KCK KGF KPF HFF HFF HFF HFF HEK HEK
INK IDF IDF IDK IDK IDK IDK IDK IIF IIF
IIF IIF IIF IIK IIK IIK IIK IIK IKF IKF
IKF IKF IKF IKF IKF IHF IHF IHF IHK IHK
IHK ICF ICF ICN ICK ICK ICK IGF IGF IGF
IGF IGK IPF IPF IPF KFF KFF KFF KFF KEF
KEF KEK KNK KNK KNK KDK KIP KKF KCF KCF
KCK KCK KGF KPF HFF HFF HFF HFF HEK HEK
#! Qua#tile .#! Qua#tile .++/ /
st Qua#tile .st Qua#tile .++/ /
Inte#qua#tile 8ange Inte#qua#tile 8ange ++ ) ) ++ ) GF ) GF
*ontly Rent "or :
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An average distance that a score deviates from the mean
Set A * * * *
Set B * * * *
Set C
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9a#iance9a#iance
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'he va#iance is com$ute! as "ollo%s 'he va#iance is com$ute! as "ollo%s
'he va#iance is the 'he va#iance is the ave#age o" the squa#e!ave#age o" the squa#e!
!i-e#ences!i-e#ences ,et%een each !ata value an! the mean,et%een each !ata value an! the mean
"o# a"o# asam$lesam$le
"o# a"o# a$o$ulation$o$ulation
σ µ 2
2
= −∑ ( ) x
N i s
x
i
x
n
2
2
1= −∑ −( )
a# ance o# #ou$eData 0o# sam$le !ata0o# sam$le !ata
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$$
0o# $o$ulation !ata0o# $o$ulation !ata
( )2
2
n
x x f ii s ∑
−=
( ) N
x f ii2
2 ∑ −= µ
σ
Stan!a#! DeviationStan!a#! Deviation
'h'h t ! ! ! i tit ! ! ! i ti " ! t t i th iti" ! t t i th iti
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'he 'he stan!a#! !eviationstan!a#! !eviation o" a !ata set is the $ositiveo" a !ata set is the $ositive
squa#e #oot o" the va#iancesqua#e #oot o" the va#iance
It is measu#e! in theIt is measu#e! in the same units as the !atasame units as the !ata** makinmakin it mo#e easily inte#$#ete! than the va#ianceit mo#e easily inte#$#ete! than the va#iance
'h t ! ! ! i ti i t ! " ll'he stan!a#! !e iation is com$ute! as "ollo s
Stan!a#! DeviationStan!a#! Deviation
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'he stan!a#! !eviation is com$ute! as "ollo%s 'he stan!a#! !eviation is com$ute! as "ollo%s
"o# a"o# a
sam$lesam$le
"o# a"o# a
$o$ulation$o$ulation
s s= 2 σ σ = 2
Coe@cient o" 9a#iation
'h'he @ i t " i ticoe@cient o" va#iation i !i t h l thin!icates ho% la#ge the
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'he coe@cient o" va#iation is com$ute! as "ollo%s 'he coe@cient o" va#iation is com$ute! as "ollo%s
1 0 0 %
s
x
×
'he 'he coe@cient o" va#iationcoe@cient o" va#iation in!icates ho% la#ge thein!icates ho% la#ge the
stan!a#! !eviation is in #elation to the meanstan!a#! !eviation is in #elation to the mean
"o# a"o# asam$lesam$le
"o# a"o# a$o$ulation$o$ulation
1 0 0 %
σ
µ
×
Measu#e o" relative !is$e#sion
oe c en o a# a on.Continue!/
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• Measu#e o" relative !is$e#sion
• Al%ays a R• C9 is the stan!a#! !eviation
e1$#esse! as $e#cent o" the mean
• (se! to com$a#e t%o o# mo#eg#ou$s
• 3eakness C9 is un!e5ne! i" the
mean is Le#o o# i" !ata a#e negative• 'hus* C9 is use! only "o# va#ia,les
%hose values a#e [F
E1am$le Continue!E1am$le Continue!
iven the "ollo%ing monthly #ent $#ices "o# F a$a#tments 5n!iven the "ollo%ing monthly #ent $#ices "o# F a$a#tments 5n!
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I N K I D F I D F I D K I D K I D K I D K I D K I I F I I F
I I F I I F I I F I I K I I K I I K I I K I I K I K F I K FI K F I K F I K F I K F I K F I H F I H F I H F I H K I H K
I H K I C F I C F I C N I C K I C K I C K I G F I G F I G F
I G F I G K I P F I P F I P F K F F K F F K F F K F F K E F
K E F K E K K N K K N K K N K K D K K I P K K F K C F K C FK C K K C K K G F K P F H F F H F F H F F H F F H E K H E K
I N K I D F I D F I D K I D K I D K I D K I D K I I F I I F
I I F I I F I I F I I K I I K I I K I I K I I K I K F I K FI K F I K F I K F I K F I K F I H F I H F I H F I H K I H K
I H K I C F I C F I C N I C K I C K I C K I G F I G F I G F
I G F I G K I P F I P F I P F K F F K F F K F F K F F K E F
K E F K E K K N K K N K K N K K D K K I P K K F K C F K C FK C K K C K K G F K P F H F F H F F H F F H F F H E K H E K
*ontly Rent "or :< A$artments*ontly Rent "or :< A$artments
iven the "ollo%ing monthly #ent $#ices "o# F a$a#tments* 5n!iven the "ollo%ing monthly #ent $#ices "o# F a$a#tments* 5n!va#iance* stan!a#! !eviation* an! the coe@cient o" va#iationva#iance* stan!a#! !eviation* an! the coe@cient o" va#iation
use equations & E1celuse equations & E1cel
9a#iance9a#iance
SolutionsSolutions
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× = × = K I &C IE F F R E F F R E E & E K R
I P F &G Fs
N
N . / N * P P H & E HE
i sn
−= =−∑
NN P P H & I C K I & C Is s= = =
thethe
stan!a#!stan!a#!!eviation is!eviation isa,out Ra,out Ro" o" o" theo" themeanmean
Stan!a#! DeviationStan!a#! Deviation
Coe@cient o" 9a#iationCoe@cient o" 9a#iation
Note thatNote that C9 is the stan!a#! !eviation e1$#esse! asC9 is the stan!a#! !eviation e1$#esse! as$e#cent o" the mean$e#cent o" the mean
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A 2#o,lem (sing E1cel• A private research
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organi=ation studing
families in various
countries reported
the following data for
the amount of time &0
ear old children
spent alone with their
fathers each da.
Coutr! "#me $#t% Da&(m#utes)
'elg#um 30
Caa&a
C%#a
*#la& 0
A 2#o,lem (sing E1cel.Continue!/
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• (se E1cel* ans%e# the "ollo%ing questions an! e1$lainyou# ans%e#s .#oun! all num,e#s into t%o !ecimal$laces/
- A 'he mean
- B 'he mo!e - C 'he me!ian
- D 'he th $e#centile - E 'he 5#st an! the thi#! qua#tile
- 0 'he #ange
- 'he inte#qua#tile #ange o# mi!s$#ea! -
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Statistical analysis ty$ically involves %o#king %ithStatistical analysis ty$ically involves %o#king %ith
la#ge amounts o" !atala#ge amounts o" !ata Com$ute# so"t%a#eCom$ute# so"t%a#e is ty$ically use! to con!uct theis ty$ically use! to con!uct the analysisanalysis
0#equently the !ata that is to ,e analyLe! #esi!es i0#equently the !ata that is to ,e analyLe! #esi!es i
s$#ea!sheets$#ea!sheet Mo!e#n s$#ea!sheet $ackages a#e ca$a,le o" !ataMo!e#n s$#ea!sheet $ackages a#e ca$a,le o" !ata management* analysis* an! $#esentationmanagement* analysis* an! $#esentation
MS E1celMS E1cel is the most %i!ely availa,le s$#ea!sheetis the most %i!ely availa,le s$#ea!sheet
so"t%a#e in ,usiness o#ganiLationsso"t%a#e in ,usiness o#ganiLations
Statistical Analysis (sing Mic#oso"t E1celStatistical Analysis (sing Mic#oso"t E1cel
tasks might ,e tasks might ,enee!e!nee!e! Ente# DataEnte# Data
A
7
*arts
Cost
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nee!e!nee!e! Ente# DataEnte# Data
Ente# 0unctions an! 0o#mulasEnte# 0unctions an! 0o#mulas A$$ly 'oolsA$$ly 'ools
7 Cost
/ 1!5 '!
> !2&
6 )
0 "$
'
4 "1
D E
-ean 3A>4+A;46A$:A'!8
-e"ian 3M4#IA.6A$:A'!8
-o"e 3M(#46A$:A'!8
2ange 3MA?6A$:A'!80MI.6A$:A'!8
E1cel 3o#ksheetE1cel 3o#ksheet .sho%ing !ata.sho%ing !ata//
Statistical Analysis (sing Mic#oso"t E1celStatistical Analysis (sing Mic#oso"t E1cel
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Note 8o%s F) a#e not sho%nNote 8o%s F) a#e not sho%n
A B C D
7 Customer Invoice
*arts
Cost (
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Note Columns A)B an! #o%s F) a#e not sho%nNote Columns A)B an! #o%s F) a#e not sho%n
C D E :
7
*arts
Cost (
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C D E :
7
*arts
Cost ( !2& !1$
6 ) !'
0 "$ $&$
' !&
4 "1 !")
'& !12