20. The following data summarize the results from an independent-measures study comparing three treatment conditions. M = 2 M = 3 M = 4 n = 10 n = 10 n = 10 T = 20 T = 30 T = 40 s2 = 2.67 s2 = 2.00 s2 = 1.33 a. Use an ANOVA with a = .05 to determine whether there are any significant differences among the three treatment means. Note: Because the samples are all the same size, MS is the average of the three sample variances.

b. Calculate n2 to measure the effect size for this study.