1. Explain under what conditions a researcher would use a One-Way Between-Subjects ANOVA.

2. A psychologist at a private mental hospital was asked to determine whether there was a clear difference in the length of stay for patients with different categories of diagnosis. Looking at the last four patients in each of the three major categories, the results (in terms of weeks of stay) were as follows:Diagnosis Category

Affective Disorders Cognitive Disorders Drug-Related Conditions

7 12 8

6 8 10

5 9 12

6 11 10

Using alpha = 0.05, is there a significant difference in length of stay among diagnosis categories? Show all five steps of hypothesis testing.

3. Compute the means and standard deviations for each group.