A psychologist would like to examine the effects of different testing methods on the final performance of college students. One group has regular quizzes (n=4), one group has three large exams (n=4), and the third group only has a final exam (n=4). At the end of the course, the psychologist interviews each student to get a measure of the student's overall knowledge of the material.

QuizzesExamsFinal Only

410N= 12

642G= 36

350X²= 164

722

T=20T=12T= 4

SS=10SS=10SS= 4

1. What are the null and alternative hypotheses?

2. Compute SS_totalSS_betweenand SS_within

3. Compute df_total, df_between, and df_within

4. Compute the variance between treatments (MS Between) and variance within treatments (MS Within)

5. What is the F-ratio?

6.Using the F-Distribution table, find the critical value for a hypothesis test where = .05.

7. Should the researcher reject the null hypothesis? Why or why not?

8. Should the researcher do follow-up testing? Why or why not?