Scuba-diving trips. The mailing list of an agency that markets scuba-diving trips to the Florida Keys contains 65% males and 35% females. The agency calls 30 people chosen at random from its list.
(a) What is the probability that 20 of the 30 are men? (Use the binomial probability formula.)
(b) What is the probability that the first woman is reached on the fourth call? (That is, the first 4 calls give MMMF.)