31. Given the following data, using a two-tailed test at the .01 level of significance, compute the following:

Participants	Pretest	Posttest
ABC RRH JMB MEM EAG AMB AAG JOK MCK ECT	22 29 22 24 26 28 22 26 31 22	28 24 30 29 31 27 26 21 26 24

a. Sample mean of difference scores, XD.

b. Sample variance and sample standard deviation.

c. Estimated standard error difference scores. d

. Population mean of difference scores, D.

e. Samples t-score.

f. The critical t-score.

34.. Given the following recall data from a Picture-Word memory study, using a two-tailed test at the .01 level of significance, compute the following:

Participants	Pictures	Words
DAV ASV AGP AMM JCL WAA ABR TRB ACG IAM	14 22 19 16 18 13 20 22 18 15	14 13 12 11 15 18 20 18 19 17

a. Sample mean of difference scores, XD.

b. Sample variance and sample standard deviation.

c. Estimated standard error difference scores.

d. Population mean of difference scores, D.

e. Samples t-score.

f. The critical t-score value.

h. Compute the effect size.