A population of N alligators is to be sampled in order to obtain an approximate measure of the difference between the proportions of sexually mature males and sexually mature females. Obviously, this parameter has important implications for the future of the population. Assume that n animals are to be sampled without replacement. Let Y1 denote the number of mature females and Y2 the number of mature males in the sample. If the population contains proportions p1 and p2 of mature females and males, respectively (with p1 + p2 < 1), find expressions for E Y1 n Y2 n and V Y1 n Y2 n . 5.1

Statistics 350 Fall 2008 Exam 1 Explanations 1. Observe that the distribution is roughly bell-shaped. a. The bulk of the data lies in the 100-120 range, so the median should too and only 110 is reasonable. Another way to see this is to realize that in a symmetric distribution, the mean and median should be the same. b. Since the histogram is bell-shaped,...