Find the expected number of boys in a family with 8 children, assuming the sex distribution to be equally probable.
Let n and p be the parameters of the binomial distribution.
Let, p = probability of having a boy in the family
Given, p = q
Since, p + q = 1
⇒ p + p = 1
⇒ 2p = 1
Given, n = 8
The expected number of boys = np
= 4
The expected number of boys = 4