Question

Parents have always wondered about the sex of a child before it is born. Suppose that the probability of having a male child was 0.5, and that the sex of one child is independent of the sex of other children. What is the probability of having exactly 3 girls out of 4 children? Round your answer to four decimal places.

Answer 1

Solution:

Given:

n = number of children = 4

Probability of male = 0.5

Probability of female = 0.5

x = number of girl child follows a Binomial distribution with parameter n = 4 and p = probability of girl = 0.5

Find:

P( X = 3) =............?

Binomial probability formula :

Where q = 1 – p = 1 - 0.5 = 0.5

thus