Question

Clinical depression is a serious and sometimes debilitating disease. It is often treated by antidepressants such as Prozac and Zoloft. recent studies may indicate another possible remedy. Researchers took a random sample of people who are clinically depressed and divided them into three groups. The first group was treated with antidepressants and light therapy, the second was treated with a placebo and light therapy, and the third group was treated with a placebo. Whether the patient showed improvement (code=1) or not (code=2) and the group number are stored in the data set below. Can we infer that there are differences in improvement between the three treatment groups? That is, to test

Hypotheses:

H₀ : “Treatment group” and “improvement” are independent

H_A:“treatment group” and “improvement” are dependent

Group	Improvement
3	1
2	2
2	1
1	2
3	2
1	1
1	1
2	1
1	1
1	1
2	1
1	1
1	1
1	2
3	1
2	1
2	2
2	1
3	2
1	1
3	1
1	2
1	1
3	2
3	2
3	1
1	2
3	2
3	1
3	1
1	2
1	2
3	2
2	2
2	2
3	2
2	1
3	2
2	1
2	2
1	1
3	2
2	1
1	1
3	2
2	1
2	1

Answer 1