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Lesson 1-1Introduction to
StatisticsYou will learn to…* define statistics * define vocabulary associated with statistics
The word statistics is derived from the Latin word status, meaning
“state.”
3 reasons for studying statistics:
1) to understand results of studies done2) to be able to conduct our own research3) to become better consumers and citizens
Buying a car
Medicine
Source: Viagra.com
Car insurance
18 year old male$842.30
Car insurance
18 year old female$661.70
Car insurance
Stats in USC Colleges• Required• College of Arts and
Sciences – Science Departments
• Moore School of Business• College of Education – any
BS and Early Childhood• College of Engineering and
Information Technology• College of Pharmacy• Arnold School of Public
Health
• Optional• College of Arts
and Sciences – Arts Departments
• College of Education – any BA and Elementary
• School of Music
Sample Schedule USC School of Business
Third Semester• ECON 221 Principles of Microeconomics • MGSC 290 or Computers in Business or
MGSC 291 Probability and Statistics • MGMT 250/ENGL 463 or Professional
Communication or ENGL 282-286 Fiction, drama, poetry, or American or British literature
• ACCT 225 Introduction to Financial Accounting • Liberal Arts Philosophy, history, political
science, geography, foreign language, etc.
USC Nursing:General Education Requirements
• General education course selections must meet University general education requirements.
• English: ENGL 101-102 or higher• Social Sciences: Two courses from one of
these: sociology or psychology. One course must cover life-span content.
• Analytical Reasoning: To be satisfied in one of the following ways: 1) STAT 110 and MATH 122 or 2) STAT 110 and STAT 201
USC: Hotel Recreation Tourism Management
a. MATH 122 or 141, plus an additional course from PHIL 110 or 111, mathematics (at the next higher level), computer science (above CSCE 101), or statistics
b. Two courses from one of the following fields--Philosophy (110 and 111 only) or computer science (above CSCE 101) or statistics
Majors of USC Students in one STAT 110
Nursing
HRTM
Early childhood
Nursing
French/Pub Rels
Entertain. Mgt
Crim Just
Poli Sci & Cr J
Early childhood
Early childhood
Broadcast Jour
Nursing
HRTM
Poli Sci
Nursing
Jour/Mass Comm
Nursing
psych/premed
Business
Nursing
Broadcast Jour
Public Relations
Fashion Merch.
HRTM
Print Journalism
Crim Just
Early childhood
Broadcast Jour
Public Relations
What is Statistics?
Collect, Organize, Analyze, and Interpret Data
in order to Make Decisions
Statistics can be Hocus-Pocus!
What is data?
Data consists of information from observations, counts,
measurements, or responses.
examples: 5 ft, 98˚, 2 hrs, 165 lb, male, 50 years old, 4 fat grams, 200 times at bat, 100,000 sold
Population
The collection of all things being studied.
X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X XX X X X X X X X X X X X X X X X X X X X X X X X X X X
SampleA subset of the population.
Heights of Ridge View students
Heights of Ridge View students taking
probability & statistics
1. Population? All RV students
Heights of Ridge View students
Heights of Ridge View students taking
probability & statistics
2. Sample? RV prob & stats students
Population Sample
Time & Money
RV students RV seniors
all courses math courses
students in this class
students in this class
We get every measurement or count that is of
interest.
We may get only partial information,
but that might be the most economical way to get info.
Who was surveyed?university students
How many were surveyed?1746
Explain “At home: 82%.”82% of those surveyed like to
snack at home
Why do the percents add up to more than 100%?multiple answers were allowed
Who was surveyed?employed American adultsWho did the surveying?US Labor Department
Explain “Cashiers; 3,262,120; $5.75.”# of cashiers surveyed in 1996;
median hourly pay rate
The U.S. Department of Energy conducts a survey of 800
gasoline stations to determine the average price per gallon.
3. Identify the population.
4. Identify the sample.
5. What does the data set consist of ?
all gas stations
800 gas stations
price per gallon ($)
A study of 33,043 infants in Italy was conducted to find a link between a
heart rhythm abnormality and sudden infant death syndrome.
6. Identify the population.
7. Identify the sample.
8. What does the data set consist of ?
all infants
33,043 infants
heart rate in beats per minute
A survey of 546 women found that more than 56% are the job of
paying bills in their household.
9. Identify the population.
10. Identify the sample.
11. What does the data set consist of ?
all women
546 women
Yes or No – Are you the primary person in your household who pays the bills?
Parameter:A numerical description of a population.
Statistic:A numerical description of a sample.
P
* data from the population
S
* data from a sample
Parameter
12. The average income of all people in the U.S. in 2002.
13. The average income of people from three U.S. states in 2002.
Is the fact a parameter or statistic?
14. A survey of a sample of workers reported their starting salary
Statistic
Is the fact a parameter or statistic?
15. Starting salaries for the 2005 graduates from USC
16. The number of students with Cingular cell phone service in a random check of classrooms
Parameter Statistic
Parameter:A numerical description of a population.
Statistic:A numerical description of a sample.
P
* data from the population
S
* data from a sample
Parameters are fixed in value,while statistics vary in value.
Two Branches of Statistics
1) Descriptive Statistics
2) Inferential Statistics
* report the facts discovered in the survey
* use sample data to make conclusions about an
entire population* estimation, prediction, probability
POPULATION of women
N = 130,000,000
Whole Population AvailableFind the average height
of women 18 - 24
Collect Data
Describe Population
Descriptive
Statistics
POPULATION of women
N = 130,000,000
SAMPLE of women
n = 1000
Inferential
Statistics
Whole Population NOT AvailableFind the average height
of women 18 - 24
Collect Data
Use sample to estimate description
of population
Take Sample
17. 1000 U.S. teens were surveyed. 72% of the girls and 58% of the boys had after school jobs.
72% of the girls and 58% of the boys had after school jobs.
We predict that a higher percentage of teen girls have after school jobs.
Descriptive statistics:
Inferential statistics:
18. In a recent survey of 1000 adults, 47% said using a cell phone while driving should be illegal.
47% of 1000 U.S. adults believed that using a cell phone while driving should be illegal.
Based on a recent survey, about half of the population believe that using a cell phone while driving should be illegal.
Descriptive statistics:
Inferential statistics:
It’s Time to Practice!
Assignment 1.1
Lesson 1-2Types of Data
You will learn to…* classify data * identify types of measurements
Qualitative data
Examples:
Data that cannot be measured or counted
gender, favorite class, religious preference, eye color, hair color,
geographical location, zip code
characteristic or categorical
Quantitative data
Examples:age, heights, weights, temperatures, grades,
time, money
Data that can be measured or counted
numerical data
Qualitative or Quantitative data?
1. ID numbers of the students in this class
2. temperature each day this week
3. jersey numbers of the players on a team
4. vehicle models
qualitative
5. price of vehicles
quantitative
Nominal Data > list of categories, names, labels, or qualities
Examples: type of car you drive, your jersey number,
college you want to attend, eye color, hair color, gender, zip code
> order (rank) cannot be assigned to the categories
Ordinal Data> data that is ordered or ranked
Examples: race outcomes (1st,2nd,3rd), grade (A,B,C,D), top 5 sports teams, rating (good, better, best)
Decide whether the data is nominal or ordinal. Why?
1. highest level of education
2. marital status
3. zip code
nominal
4. rating for first impression of store
ordinal
Discrete Data > countable
Examples: number of courses you are taking, number of pairs of shoes you own,
number of CDs you own,score at figure-skating competition
cost of concert tickets
> usually integers only – no decimals or fractions
9.9, 9.5, 8.8, 10.0, 9.3
Continuous Data > not countable
Examples: weight of a bookbag,
minutes it takes for you to get to school, inches of rain fall
> weight or measurement
time is continuous
Decide whether the data is continuous or discrete. Why?
1. students wearing blue jeans
2. height of students
3. money each student has
discrete
4. weight of each bag of M&Mscontinuous
variable
qualitative
quantitative
nominal
ordinal
discrete
continuous
Lesson 1-3
StatisticalDesign
You will learn to…* identify ways to collect data * identify ways to get a sample of the population for a study
The goal of every study is to collect data and use it to
make a decision.
If the data collection process is flawed, then
the results are not valid.
Designing a Statistical Study
2) develop a plan for collecting data
1) identify data of interest & identify population
3) collect data
5) report inferential statistics
4) report descriptive statistics
6) identify any possible errors
Data Collection
1) Take a Census
2) Use a Sampling (entire population)
3) Create a Simulation (part of a population)
4) Conduct an Experiment
(reproduce conditions - crash dummies)
(study group & control group)
Which method of data collection?
1. the effect of changing flight patterns on the number of airplane accidents
2. the effect of aspirin on preventing heart attacks
simulation
experiment3. the weights of all linemen in the National Football League census
4. U.S. residents’ approval rating of the president sample
ExperimentEveryone in class will look at a
picture. Without saying anything, you will write down what you see
in the picture.
If you are sitting in seat 1-13, close your eyes, cover your eyes,
or put your head down.
Do not say anything.
Do not write anything.
Just look at the picture.
Without saying anything, write down
what you see in the picture.
Watch this video.In this video, 3 kids have white
shirts and 3 kids have black shirts. Focus on the kids in
white and count the number of times they pass the ball to a
different person.
When time and money prevent you from
collecting data from the entire population…
Data Collection
1) Take a Census
2) Use a Sampling (entire population)
3) Create a Simulation (part of a population)
4) Conduct an Experiment
(reproduce conditions - crash dummies)
(study group & control group)
5 Sampling Techniques (ways to choose a sample)
Random Sample:> Each member of the population has an equal chance of being selected.
(heights of students)
Using the Calculator
>MATH > PRB > randInt(
randInt (begin, end, # in sample)
randInt (1, # in population, # in sample)
How can we all get the same data?
1 rand
Stratified Sampling
> divide the population into groups using some characteristic
> select a few members from each group
Stratified Sampling
Low Income Middle
Income
High Income
X XX
X
X X
Stratified Sampling
A Hall
B HallC Hall
D Hall
Freshmen Sophomores
Juniors Seniors
Proportional Stratified Sampling
Low Income Middle
Income
High Income
2,000 families
500families
500 families
select 50 select 200
select 50
Cluster Sampling > population is divided into groups > use one group for the sample
Cluster Sampling
Low Income Middle
Income
High Income
Cluster Sampling Freshmen Sophomores
Juniors Seniors
Systematic Sampling
> every nth number from the population is included in the sample
Systematic Sampling
X X X
X X X
Choose every household 3rd
Systematic Sampling
Choose every 5th student
Convenience Sampling
> subjects used because they are convenient and available > volunteer sampling
* telephone survey
* survey at a shopping center
Identify the sampling technique used for each study.
5. select a class at random and question each student in the class
6. divide the students by grade level and question some students in each
grade level
cluster stratified
7. assign each student a number, generate random numbers, and question each student whose number is selected
Identify the sampling technique used for each study.
random
8. choose a starting point and question every 25th student
systematic
The commonly used sampling methods that often results in
biased samples are _______________________
• Volunteer sampling• Convenience sampling
The Statistical Process:
1) identify _________2) plan __________
3) collect & analyze ______
4) describe ______
5) make inferences about __________6) Identify possible ________
population
investigationdata
sample
populationerrors
It’s Practice Time!
Assignment 1.3
Ch 1 Review Assignment