Question

1. Provide two examples that you did not find in the book of when to use a related samples t test.

2. A major university would like to improve its tarnished image following a large on-campus scandal. Its marketing department develops a short television commercial and tests it on a sample of n = 7 subjects. People's attitudes about the university are measured with a short questionnaire both before and after viewing the commercial. The data are as follows:

Person	X1 (Before)	X2 (After)
A	15	15
B	11	13
C	10	18
D	11	12
E	14	16
F	10	10
G	11	19
H	10	20
I	12	13
J	15	18

(a) Is this a within-subjects or a matched samples design? Explain your answer.

(b) Conduct a hypothesis test (showing all the steps) to determine if the university should spend money to air the commercial (i.e., did the commercial improve the attitudes?) Assume an alpha level = 0.05. You may use SPSS but not required.

3. For the sample difference scores below, determine if the sample differs from D = 0. Use alpha = 0.01.

Answer 1