Refer to Exercise 10.38, which compared two therapies for depression patients. Suppose that in a different experiment, only four patients took part; two were randomly assigned to the group that received therapy 1 and the remaining two to the group that received therapy 2. The following table shows the improvement scores for these 4 patients.

a. List all six possible ways these four patients could have been assigned to the two therapies. That is, give all six possible ways of dividing the four patients into two groups of two patients each.
b. Using the observed improvement scores shown in the table, find the sample means in each group and their difference under each possible assignment.

Refer to exercise 10.38

clinical psychologist wants to choose between two therapies for treating severe cases of mental depression. She selects six patients who are similar in their depressive symptoms and in their overall quality of health. She randomly selects three of the patients to receive Therapy 1, and the other three receive Therapy 2. She selects small samples for ethical reasons€”if her experiment indicates that one therapy is superior, she will use that therapy on all her other depression patients. After one month of treatment, the improvement in each patient is measured by the change in a score for measuring severity of mental depression. The higher the score, the better. The improvement scores are
Therapy 1: 30, 45, 45
Therapy 2: 10, 20, 30
Analyze these data (you can use software if you wish), assuming equal population standard deviations.

Transcribed Image Text:

Patient: Therapy: Score: 3 4 1 2 60 30 30 20