An investigator conducts a study to examine the benefits of psychotherapy for individuals with depression. Specifically, the investigator predicts that depressed individuals who receive psychotherapy in addition to drug therapy for depression will display significantly lower levels of depression than persons with a diagnosis of depression who receive only drug therapy. The investigator assigns 10 subjects to each of the two groups stated above. After three months the investigator measures depression using a scale in which higher scores reflect higher levels of depression.Psychotherapy plus drug therapy group: 23, 19, 16, 18, 15, 22, 16, 18, 19, 20 Drug therapy only: 24, 27, 26, 28, 29, 24, 26, 25, 22, 28

Write the null and alternate hypothesis, determine the appropriate t-test for each of the following problems, decide upon a decision rule, draw the rejection region, and write a statement that describes the relationship the researcher is entitled to make.