3. The following are scores for 3. five participants in an investigation having a pretest–posttest design:

Participant ABCDE Pretest 12 6 8 5 9 Posttest 9 8 6 1 6

(a) Compute SSpre, SSpost, and rpre,post.

(b) From SSpre and SSpost, determine s2 pre and s2 post.

(c) Compute sXpre Xpost

(d) Test H0: μpre − μpost 0 against H1: μpre −μpost 0 (α 05)

(e) Draw final conclusions.