Use the normal distribution to find a confidence interval for a difference in proportions p1 p2 given the relevant sample results. Give the best estimate for p1 p2, the margin of error, and the confidence interval. Assume the results come from random samples. A 95% confidence interval for p1 p2 given that p1 = 0.72 with n1 = 500 and p2 = 0.68 with n2 = 300. Note that z = 1.96.