Computers & Stastic Method

8/13/2019 Computers & Stastic Method

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DATA

PROCESSED THROGH

COMPUTER ANDSTATISTICAL METHODS

INFORMATION

Figures do

not lie butliers do

figure!!



• Lots of data are generated by various

activities everyday

• Data does not mean numerical facts

alone…it includes text, pictures as

well as voice!!• Some one has to compile that large

data and make valuable information

• Statistics and Computers help in this process

Statistics

today is not

an ornament but a

necessary

tool!



• Data flows from sources like..

• Village Level

• Mandal Level

• District Level

• State Level

• Region Level

• Country Level

• Global Level

• A database is a collection of records

(or data files) combined and treated

as a unit for information retrieval

Data flows

like flood

water!!

Database is

like a

Check

dam!



StatisticalDatabases!

• We have statistical databases on

various aspects like• Food grains

• Blood Banks

• Tax Payers

• Agricultural Output• Share Market and many more…..

• The DATA should be converted intoinformation (reports) by applying

Data Analysis Tools



• Examining data for its relevance

• Preparation of tables

• Graphic display of information• Estimating the unknown

• Example: Agricultural output by Crop-

cutting experiments

• Establishing functional relationship

between causes and effect

• Computing the Growth rates

• Understanding the Trends and making

forecasts … and many more!

• Preparing a document stating the

methodology and interpreting the results

What is Data

Analysis?

MakingFigures

Speak

(the truth!)



• The Common and Old Method

• Physical counting of cases from data sheets

• Hand Calculations

• Reference to Statistical Books for formulae

• Bypassing complex calculations and

reporting the easy-to-do things alone!How to do?

• The Contemporary Method

• Get data into the computer• Use a statistical software

• Prepare document using a Word Processor





• A new health insurance scheme is

introduced by a company for its

employees

• The management wishes to know the

reaction of its employees to the new

scheme

• Opinions were collected from 50employees on several aspects like

• Age, Gender, Marital Status,

Education level, Presentarrangements for health check

up, monthly income and Concept

Rating.

A survey

on health

insurance



• A questionnaire has been designed and

used for collecting data

• Opinions were sought on a five point

scale (multiple choice-tick one only)

• Coding of responses is as follows.

• Extremely interested 5

• Interested 4

• Indifferent 3

• Not interested 2

• Not at all interested 1

Collection

of data

with

suitable

coding



• Age – (initially no coding )

• actual years

• Gender• Male M

• Female F

• Marital Status

• Married M

• Single S

• Monthly income

• Less than Rs.1000 1• Rs.1000 to Rs.2999 2

• Rs.3000 to Rs.4999 3

• Rs.5000 & above 4

Coding for

personal

factors



• Education

• Below Higher Secondary 1

• Higher Secondary 2

• Graduation 3

• Post-graduation 4• Present Arrangement

• Private doctor-own expenses 1

• Government/Corporate Hospitals 2

• Partial reimbursement 3

• Full reimbursement 4

Coding

for personal

factors



• Analysis is based on the questions for

which the data is expected to provide

answers

Analyzethe Data!

• Some questions

• Identify how many are interested in the

new scheme and how many are either

indifferent or not interested• Cross tabulate them along Gender, Age,

Education, marital status etc

• Is there any relationship between the

income level and the type of response?

• Identify the factors influencing the

adoption to new scheme?

• What else the data speaks!



• Data Entry

• -The First Step

• Analysis with Software

• – The Second Step



• The data collected from the field contains

filled-in questionnaires or sheets

• Each sheet must have a serial number

• The sheets should be converted into a data

file for use in computer

• We can probably divide the work and makemore than one file and assign the work to

Data Entry Operators

• The Data Entry Design should be well

planned and be common for all operators

• These data files can be pooled up if

necessary to make a project-data-file

The

physicalstructure

of data



TAKING

DATA FROM

BOOK TO

COMPUTER

Data should be arranged as separate records one for each

individual (entity)

The data should be numeric for carrying out any analysis

Names and other labels will not go in for analysis but can be

used for reporting

Suitable coding should be defined before entering data in the

computer



• There are many packages for data entry

like..

• FoxPro• Lotus

• MS-Excel

• MS-Access

• Oracle• On-line formats

Software

for data

entry and

data

analysis• Packages for Statistical Analysis

• SPSS

• SAS

• MINITAB

• SYSTAT



A VISIT TO EXCEL



MAKING ADATA FILE

Open Excel

On the title bar of the Excel windowthe file name appears as MicrosoftExcel Book1

It usually contains three sheetsnamed Sheet1,Sheet2 and Sheet3

In Sheet1 start entering the datafrom cell A1

Reserve the f i rst row for columnheadings like Sno, Age, Gender etc

Key in the data row wise or columnwise (press ENTER key after eachentry)

Save the file with a suitable name in

a Folder meant for this project



A SAMPLEDATA SHEET

File Name: Food – Folder: D:\Statman



NOT THE

CORREC

T STYLE

OF DATA

ENTRY



THE RIGHT

WAY!





ANALYTIC

AL

FEATURE

S

IN EXCEL

Finding sums

Data sorting and Filtering

Making one dimension tables

Cross tabulations

Creating different types of graphs

Making abstracts from worksheets

Changing the styles of presenting data

Linking Excel report to a document



SOME

TIPS

INDATA

HANDLIN

G

Selecting a part of data

Sorting

Filtering

Column width

Cut, Copy & Paste

Auto Fill

Paste Special

Freeze PanesExporting Excel data to Word



D T

N LYSIS

P K

A free package of simple statistical tools is available in Excel

It is called Data Analysis Pak

It provides for analyses like

Summary statistics

Comparison of groups

Correlations

Regression analysis

Statistical tests of hypothesis

…..and many more



Data

Prepared

In

Word

Table

S NO NAME GENDER CAS TE ENGLIS H MATHS S CIENCE

1 RAJA. M B SC 60 27 45

2 ANITHA. R G SC 55 44 36

3 NEELIMA. K G ST 46 54 654 SIVARAJAN. A B OC 35 47 28

5 MUTHU. B G OC 20 46 35

6 GOPAL.R B OC 54 50 45

7 BEENA. A G BC 63 46 64

8 ACHUTAN. S B BC 54 52 65

9 PRADEEP.M B BC 35 40 54

10 PERUMAL. S B OC 25 36 45

11 VARADAN. D B OC 28 40 38

12 DIVYA. T G BC 64 56 37

13 VASUMATHI. D G BC 37 45 54

14 ANDAL. B B SC 63 44 36

15 JAYA. L G ST 56 52 63

16 RAMAN. N B BC 45 48 54

17 MUREGESH. M B ST 50 46 68

18 GANESH. L B ST 35 38 65

19 SASIKALA. R G BC 52 50 54

20 VALLI. M G SC 41 55 58

It is enough to copy the Word Table and

Paste in Excel!



We have

got it

in Excel!





Frequency distribution of students




by caste (one-way table)

Count of SNO

CASTE Total

BC 7OC 5

SC 4

ST 4Grand Total 20





by Caste and Gender (two-way table)

Count of SNO GENDER

CASTE B G Grand Total

BC 3 4 7

OC 4 1 5SC 2 2 4

ST 2 2 4

Grand Total 11 9 20

Can we do this with hand calculations if

there are thousands of cases?

Not impossible but difficult to do!



Can wemake a

Frequency

table withgiven class

intervals?

Soft

Skill

USE

STATISTICAL

FUNCTIONS

CERTAINLY !



Built-in

Functions

In Excel

ENGINEERING FUNCTIONS



Built-in

Functions

In Excel

STATISTICAL FUNCTIONS



AQUIRE

SKILL

BY

DOING…

DEMO FOLLOWS…..

M ki F T bl



Making a Frequency TableBody length (cm) of 120 fish

16.7 12.6 15.1 13.4 16.7 17.7 14.6 18.0 15.8 14.8

16.9 13.7 16.0 14.4 15.3 16.4 12.8 11.5 13.4 16.0

14.3 18.3 18.3 16.6 13.2 17.5 16.9 15.2 14.0 17.7

13.8 13.2 13.7 18.4 17.1 13.9 20.5 13.2 14.9 17.4

16.9 15.0 17.2 14.5 13.6 16.6 13.0 17.9 18.8 17.915.3 18.9 14.8 16.0 18.5 13.3 19.2 16.2 14.4 17.8

15.6 18.0 15.8 15.7 20.6 13.5 16.3 15.1 14.3 10.7

15.6 15.4 12.6 15.4 17.2 15.1 14.1 13.1 15.4 13.5

12.7 14.1 12.2 16.6 17.0 15.6 14.7 18.7 18.3 13.2

19.5 14.3 16.2 15.9 16.8 15.3 17.3 13.1 12.3 17.0

16.9 12.4 15.4 17.6 16.2 14.4 18.8 13.5 14.2 14.8

12.9 13.5 15.1 14.2 15.3 14.8 15.2 14.4 16.1 18.2

Prepare a frequency table using Excel



We use

the Paste

function‘FREQUENCY’

min 10.7

max 20.6

range 9.9

interval 2lower limit upper limit upper bound (BIN) freq

10 12.0 11.9 2

12 14.0 13.9 26

14 16.0 15.9 43

16 18.0 17.9 3118 20.0 19.9 16

20 22.0 21.9 2

Class freq

10 - 12 2

12 - 14 2614 -16 43

16 - 18 31

18 - 20 16

20 - 22 2

120

Learn

more by

‘Do it yourself’



You can

also

construct

a

Bar Chart

Class freq

10 - 12 2

12 - 14 26

14 -16 43

16 - 18 3118 - 20 16

20 - 22 2

TOTAL 120



ADVANCED FEATURES



Data

Analysis

Pak



Data

Analysis

Pak



Thet-test

Sugali Yanadi

20.43 17.7

22.51 21.4

18.99 20.7

20.49 19.3

23.12 21

25.63 17.9

18.08 18.6

20.63 18.5

22.55 18.2

22.43 20.3

22.77

23.23

Body Mass Index of

Tribal Groups

Is the Average BMI

Same for the two

groups ?



t-testoutput

Sugali YanadiMean 21.73833 19.36

Variance 4.319215 1.898222

Observations 12 10

Pooled Variance 3.229768Hypothesized Mean Difference 0

df 20

t Stat 3.090767

P(T<=t) one-tail 0.002882

t Critical one-tail 1.724718

P(T<=t) two-tail 0.005764

t Critical two-tail 2.085962

t-Test: Two-Sample Assuming Equal Variances



p-p Plot



WIDE RANGE OF APPLICATIONS

Control chartsForecasting

Curve fitting

Solver for optimization

College Admissions

Evaluation of test scores & ranking

…and many more!



The best way of learning

Excel is to work with Excel



Statistics Made Simple -

Do it yourself on PC

By

K.V.S.Sarma

Prentice Hall India



Thank you

Documents

Computers & Stastic Method