14. A high school social studies teacher decides to conduct action research in her classroom 14.

by investigating the effects of immediate testing on memory. She randomly divides her class into two groups. Group 1 studies a short essay for 20 minutes, whereas Group 2 studies the essay for 20 minutes and immediately following takes a 10-minute test on the essay. The results below are from a final exam on the essay, taken one month later:

Group 1 (Studied Only) Group 2 (Studied and Tested)

n1 15 ΣX1 300 SS1 171 n2 15 ΣX2 330 SS2 192

(a) Set up the appropriate statistical hypotheses.

(b) Perform the test (α 05).

(c) Draw final conclusions.