Chapter 15, Problem 7E

Send more money The philanthropic organization in Exercise 3 expects about a 5% success rate when they send fundraising letters to the people on their mailing list. In Exercise 3, you looked at the histograms showing distributions of sample proportions from 1000 simulated mailings for samples of size 20, 50, 100, and 200. Here are both the theoretical and observed statistics for these simulated samples:

1. a) Looking at the histograms of Exercise 3, at what sample size would you be comfortable using the Normal model as an approximation for the sampling distribution?
2. b) What does the Success/Failure Condition say about the choice you made in part a?