3)	In a public opinion poll, approximately 85% of Americans felt that having a police officer on patrol in the neighborhood made them safer than having no police officer on patrol. The margin of error reported was 3%. Construct an interval estimate using these figures.
Answer
4)	For each of the following confidence levels, look up the critical z values for a two-tailed test.
4a) 90% (Hint: 5% in each tail):	Work:
4b) 95% (Hint: 2.5% in each tail):	Work:
5)	Remembering that a meta-analysis calculates one mean effect size using the effect sizes of several studies, assume you are conducting a meta-analysis over a set of five studies. The effect sizes for each study are: d= .65, d = .19, d = .42, d = .08, d = .70
5a) Calculate the mean effect size of these studies.
5b) Use Cohen's conventions to describe the mean effect size you calculated in part (a).