The research paper on culturally targeted therapy described in Exercise 8.59 reported the following: Across all 76 studies, the random effects weighted average effect size was d = .45 (SE = .04, p < .0001), with a 95% confidence interval of d = .36 to d = .53. The data consisted of 72 nonzero effect sizes, of which 68 (94%) were positive and 4 (6%) were negative. Effect sizes ranged from d = −48 to d = 2.7. 

a. What is the confidence interval for the effect size?

b. Based on the confidence interval, would a hypothesis test lead us to reject the null hypothesis that the effect size is zero? Explain.

c. Why would a graph, such as a histogram, be useful when conducting a meta-analysis like this one?