=+21. Send money. When they send out their fundraising letter, a philanthropic organization typically gets a return from about 5% of the people on their mailing list. To see what the response rate might be for future appeals, they did a simulation using samples of size 20, 50, 100, and 200.

For each sample size, they simulated 1000 mailings with success rate p = 0.05 and constructed the histogram of the 1000 sample proportions, shown below. Explain what these histograms say about the sampling distribution model for sample proportions. Be sure to talk about shape, center, and spread.

0.00 Sample Proportions Samples of Size 20 0.25 Number of Samples 300 200 100 0

0.00 Sample Proportions Samples of Size 50 0.15 Number of Samples 250 200 150 100 50 0

0.00 Sample Proportions Samples of Size 100 0.14 Number of Samples 150 100 50 0

Sample Proportions Samples of Size 200 0.02 0.06 0.10 Number of Samples 120 100 80 60 40 20 0