Construct a confidence interval for p 1 minus p 2 at the given level of confidence. x 1 equals395, n 1 equals 538, x 2 equals 444, n 2 equals 572, 90% confidence The researchers are 90 90% confident the difference between the two population proportions, p 1 minus p 2, is between .733 . 733 and .776 . 776.