16. The director of Academic Support Services wants to test the efficacy of a possible intervention for undergraduate students who are placed on academic probation. She randomly assigns 28 such students to two groups. During the first week of the semester, students in Group 1 receive daily instruction on specific strategies for learning and studying. Group 2 students spend the same time engaged in general discussion about the importance of doing well in college and the support services that are available on campus. At the end of the semester, the director determines the mean GPA for each group:

Group 1 (Strategy Instruction) Group 2 (General Discussion)

n1 14 X1 2 83 s1 41 n2 14 X2 2 26 s2 39

(a) Set up the appropriate statistical hypotheses.

(b) Perform the test (α 05).

(c) Draw final conclusions.