Question

The mailing list of an agency that markets scuba-diving trips to the Florida Keys contains 70% males and 30% females. The agency calls 26 people chosen at random from its list.

(a) What is the probability that 18 of the 26 people are men? (Use the binomial probability formula. Round your answer to four decimal places.)


(b) What is the probability that the first woman is reached on the 4th call? (That is, the first 4 calls give MMMF. Round your answer to four decimal places.)

Answer 1

a) probability that 18 of the 26 people are men = $\binom{26}{18}(0.7)^{18}(0.3)^{8}$ =0.1669

b)probability that the first woman is reached on the 4th call =P(first 3 are male and 4th is female) =0.7³*0.3 =0.1029