A researcher is determining if exercising 3 times a week is more effective than pharmaceuticals or psychotherapy. A total of 20 psychiatric patients were assigned to one of four treatment conditions and asked self-reported depression on a scale of 1 (depressed) to 15 (happy). Test the null hypothesis that there is no difference between exercise, antidepressants, therapy, and the control group using the following data. Please show steps to retrieve answer:
|
Treatment
|
n
|
sample mean
|
sd
|
|
Exercise
|
5
|
9
|
2.5
|
|
Antidepressants
|
5
|
10
|
2
|
|
Therapy
|
5
|
9
|
2
|
|
Control
|
5
|
7.5
|
2
|