Question

A university is examining four methods to supplement instruction. The methods have been analyzed in four separate studies, one for each method. In each study, the final exam scores of a control group of students who didn't receive any supplemental instruction were compared to those of a group who received the particular method of supplemental instruction. A one-tailed, independent samplest test (with the assumption of equal variances) was performed in each study to see if the mean for the supplemental instructional group was significantly greater than the mean for the control group. The table below summarizes the results of the four studies. The subscript "1" refers to a control group, and the subscript *2* refers to a group receiving the particular method of supplemental instruction. The values, is the pooled sample standard deviation. Note that this value was not reported in one of the studies Method A Method B Method Method D * - 64 .*,- 63 *1-63 X; - 70 Xy - 70 5-69 Not reported p=10.4 - 25 - 25 20 - 20 ni = 30 2-30 25 Suns Results of t test Save For Late

Answer 1

Ansla Stret size com be calceeloded as ,- 72 Sp. (a) Method a effect size = 163-70 0,67308 10.4 Ob Method B effect eet slze = 64–69 0.537 9.3 c) Method C effect size 0.625 64-70 9.6 8.41 302 (d) first we will of and the sp for Method a Pltsa)=0.008 s) s) a = -2.52147-6 Spx . Method effect 25 size = 63-69 D7 318 8.413 Method B < Method c < Method A C Method ] CS Scanned with CamScanner