25. Irving and Berel (2001) compared the effects of four kinds of programs (three actual programs and a control group) designed to make women more skeptical of media portrayals of female body image. After completing each program, the 110 participants were given stamped, addressed postcards that they could mail to a media activism organization (“About Face”) if they so chose. Here are some of their results:

. . . [P]ostcards were sent by approximately twice as many of the participants in the video-only condition (i.e., 36%) than in the internally oriented condition

(19% of participants returned postcards) and the externally oriented condition

(15% returned postcards). Only 5% of those in the no-intervention control group sent postcards to “About Face.” Group differences in the rate of return were significant,

213, N = 1102 = 8.79, p 6 .05, suggesting that the intervention had a differential impact on intentions to engage in media activism. (p. 109)

(a) Figure the chi-square yourself (your results should be the same, within rounding error).

(b) Figure the effect size.

(c) Explain the results to a person who has never had a course in statistics.