which of the following is NOT a reason why the procedures to estimate differences of two proportions or testing a claim about two proportions work? Choose the correct answer below. A. The pooled estimate of the common value of p1 and p2 is p=x1+x2n1+n2. B. The variance of the differences between two independent random variables is the sum of their individual variances. C. Since p1 and p2 are each approximated by a normal distribution, the difference p1−p2 will also be approximated by a normal distribution with mean p1−p2. D. The form of the confidence interval utilizes the same variance as when testing claims using hypothesis tests.