Sample size and margin of error. In Section 8.1, we studied the effect of the sample size on the margin of error of the confidence interval for a single proportion. In this exercise we perform some calculations to observe this effect for the two-sample problem. Suppose that p^1 = 0.7 and p^2 = 0.6, and n represents the common value of n1 and n2.
Compute the 95% margins of error for the difference in the two proportions for n = 40, 50, 80, 100, 400, 500, and 1000. Present the results in a table and with a graph. Write a short summary of your findings.