In a country, the survival function for women is closely approximated by s_f(x) = (1 − x/100)^1/2, while for men, it is s_m(x) = (1−x/90)^1/2. We assume that the probability of the birth of a boy is 1/2. Let N_m and N_f be the number of men and women of age x. Estimate E{N_f})E{N_m} for x = 0 and x = 50. Give a heuristic explanation for why the ratio mentioned is greater for x = 50.