1. The Hypothesis
The Role of the Normal Distribution
Confidence Levels
Difference in Population / Difference in Means
Relationships Among Treatments and Use of Nominal Data
Going From Survey to Usable Measurement

2.  The Hypothesis
H0: Mean = 60 mpg
Ha or H1: Mean > 60 mpg
Mean not equal 60 mpg
 Exhibit 17-2 – One-tailed vs. Two-tailed tests
 What you have to show
To reject the null hypothesis; Sample mean must be
outside the confidence interval (95% or what is stated as
significant by the researcher)

3.  Population mean and variance known
Does your sample fit into the confidence interval?
 Population mean and variance not known
You are making generalizations about the population
based on the sample
Increase the sample size to reduce tolerable error
Standard error of the mean from p. 391

4.  Develop the confidence interval
 Does your sample fall inside the interval?

5.  Develop 2 confidence intervals
 Is there an overlap?

6.  Chi Squared
 Degrees of Freedom
 Critical Values

7.  Spreadsheet Form
 Counts
 Different Tables