What source of variation is found in an ANOVA summary table for a within-subjects design that is not in an ANOVA summary table for a between-subjects design. Why?

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 is presented below.

Placebo

Low Dose

Moderate Dose

38

22

14

47

19

26

39

8

11

25

23

18

42

31

5

a.Run ANOVA using Excel for each of the three groups and copy/paste or screenshot your results here. Be sure that you have labeled each part of your data.

b.What would be the null hypothesis in this study?

c.What would be the alternate hypothesis?

d.Analyze the data. What are the significant differences between the three groups in the study? Be sure to cite where, specifically, you have found these differences/lack of significant differences in your data above.

Write out a formal conclusion based on the findings of this new antidepressant, as if giving a brief presentation to your colleagues & boss. Give specific details. Will the drug alleviate depression? Why/why not? What dosage would you recommend? Why? What would you share with the patients in each of the three groups within the study regarding the results? [150 - 250 word count]