In obtaining the sample size to estimate a proportion, the formula n = [z(a/2)]2 pq/E2 is used. If a reasonable estimate of p is not available, it is suggested that p = 0.5 be used because this will give the maximum value for n. Calculate the value of pq = p(1 = p) for p = 0.1, 0.2, 0.3,. , 0.8, 0.9 in order to obtain some idea about the behavior of the quantity pq.