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 counts of 240 yes out of 500 yes-or-no responses sampled for Group 1 and 450 yes out of 1000 yes-or-no responses sampled for Group 2. Note that z = 1.96.