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1
Section 1.3
The Process of a Statistical Study
HAWKES
LEARNING
SYSTEMS
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Copyright © 2008 by Hawkes Learning
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Al rights reserved.
Collect
Data
Defines
Population/
Variables
Question
Calculate
Statistic
Estimate
Parameter
Introduction to Statistics
1.3 Process of a Statistical Study
HAWKES
LEARNING
SYSTEMS
math courseware specialists
•
Observational Study
– researcher
observes data that already exists.
•
Experiment
– researcher seeks to
create data to identify cause and
effect relationships.
Types of Studies:
Introduction to Statistics
1.3 Process of a Statistical Study
HAWKES
LEARNING
SYSTEMS
math courseware specialists
•
A medical researcher wants to examine the
effects of exercise on cardiovascular health.
Experimental
•
A recording company is interested in knowing
the percentage of teenagers that download
music off of the internet.
Observational
•
A chain of grocery stores wants to know how
much the average family spends on produce
each month.
Observational
Observational Study or Experimental Study?
Introduction to Statistics
1.3 Process of a Statistical Study
HAWKES
LEARNING
SYSTEMS
math courseware specialists
•
Ask, “How will the data be gathered?”
•
Very Important:
•
It is essential that a
representative
sample
is chosen out of the
population.
•
A good
sampling frame
is the first
step to choosing a representative
sample.
The sampling frame is a list
of members of the population.
Observational Studies:
Introduction to Statistics
1.3 Process of a Statistical Study
HAWKES
LEARNING
SYSTEMS
math courseware specialists
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•
Census
•
Random Sample
•
Stratified Sample
•
Cluster Sample
•
Systematic Sample
•
Convenience Sample
Sampling Techniques:
Introduction to Statistics
1.3 Process of a Statistical Study
HAWKES
LEARNING
SYSTEMS
math courseware specialists
Census:
Every member of the population is included.
Introduction to Statistics
1.3 Process of a Statistical Study
HAWKES
LEARNING
SYSTEMS
math courseware specialists
Random Sample:
Every member has an equal chance of being selected.
Introduction to Statistics
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 Spring '10
 David
 Math, Statistical Study, Hawkes Learning Systems, math courseware specialists, SYSTEMS math courseware

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