# Hypothesis Testing for Mean Difference

P 21

A market research firm used a sample of individuals to SELFIII rate the purchase potential of a

particular product before and after the individuals saw a new television commercial about

the product. The purchase potential ratings were based on a 0 to 10 scale, with higher values

indicating a higher purchase potential. The null hypothesis stated that the mean rating

"after" would be less than or equal to the mean rating "before." Rejection of this hypothesis

would show that the commercial improved the mean purchase potential rating. Use

a = .05 and the following data to test the hypothesis and comment on the value of the

commercial.

Purchas Rating Purchase Rating

Individual After Before Individual After Before

1 6 5 5 3 5

2 6 4 6 9 8

3 7 7 7 7 5

4 4 3 8 6 6

https://brainmass.com/statistics/hypothesis-testing/hypothesis-testing-for-mean-difference-540279

#### Solution Preview

Let me list a table for the data

X1 X2 d d*d

5 6 -1 1

4 6 -2 4

7 7 0 ...

#### Solution Summary

The solution gives detailed steps of hypothesis testing on mean difference using the example of market research firm. All formula and calculations are shown. Finally, conclusion is stated clearly.