A research study was conducted to examine the clinical efficacy of a new antidepressant. Depressed patients were randomly assigned to one of three groups: a placebo group, a group that received a low...

A research study was conducted to examine the clinical efficacy of a new antidepressant.
Depressed patients were randomly assigned to one of three groups: a placebo group, a
group that received a low dose of the drug, and a group that received a moderate dose of
the drug. After four weeks of treatment, the patients completed the Beck Depression
Inventory. The higher the score, the more depressed the patient. The data are presented in
Table 1. Compute the appropriate test using 5% significant level.
TABLE 1
Placebo Low Dose Moderate Dose
38 22 14
47 19 26
39 8 11
25 23 18
42 31 5
a) What would be the null hypothesis in this study?
b) What would be the alternate hypothesis?
c) What is your Fcrit?
d) Is there a significant difference between the groups?
e) If there is a significant difference, where specifically are the differences?
f) Interpret your answer