17. Gravetter/Wallnau/Forzano, Essentials - Chapter 9 - End-of-chapter question 17 A random sample is obtained from a population with a mean of u = 20. After a treatment is administered to the individuals in the sample, the sample mean is M = 22 with a variance of s* = 9. Distribution Degrees of Freecom - 21 3500 2500 -3.0 -2.0 -1.0 0.0 2.0 3.0 -0.686 Assuming that the sample consists of n = 9 individuals, use a two-tailed hypothesis test with a = .05 to determine whether the treatment effect is significant. 1 = the critical value ist = = [ the null hypothesis. The treatment effect significant. Compute Cohen's d to measure the size of treatment effect. Estimated Cohen's d = Assuming that the sample consists of n = 36 individuals, use a two-tailed hypothesis test with o = .05 to determine whether the treatment effect is significant. t = : the critical value ist = = [ the null hypothesis. The treatment effect significant. Compute Cohen's d to measure the size of treatment effect. Estimated Cohen's d = Comparing the answers you found in the preceding two cases, how does the number of scores in the sample influence the measures of effect size? Increasing the sample size the likelihood of rejecting the null hypothesis. Increasing sample size causes in the measures of effect size