You Wish to Construct a 95% Confidence Interval to Compare

Multiple Choice

You wish to construct a 95% confidence interval to compare the mean measurement for two groups.A small pilot study yields sample standard deviations of 20 and 30 for Group 1 and Group 2,respectively.If we wish to obtain a margin of error of at most 10,what sample size should we take from each group? Assume equal sample sizes.

A) 49
B) 47
C) 50
D) 48
E) 51