Question

81. The probability that a woman will give birth to a girl during any given pregnancy is 48% a. What is the probability that a couple planning to have four children will have exactly one girl? b. What is the probability that a couple planning to have five children will have at least two girls?

Answer 1

Pre-requisite: . If x is a Binomial landom Valiable with a teials and p be the success probability in each tlail, then the probability of exactly 'k' success out of a trails is P(x= k)= ) (1-5) * Problem: Probability of birth to a girl child þ= 48% p=0.48 @ number of children n=4. probability of exactly one gul P(x=1) = ) (0.48)(0.52) = 4 (0.48) (0.52)3 = 10.26996

② number of children n=5 probability of at least two girls = P(X22) = 1- P(x=0) - P(x=1) = 1-15) (0.48)º(6.52)5– 15) (0.48) (0.52)" = 10.786500)