Question

Assume that different groups of couples use a particular method of gender selection and each couple gives birth to one baby. This method is designed to increase the likelihood that each baby will be a​ girl, but assume that the method has no​ effect, so the probability of a girl is 0.5. Assume that the groups consist of 42 couples. Complete parts​ (a) through​ (c) below. a. Find the mean and the standard deviation for the numbers of girls in groups of 42 births.

Answer 1

let p is the probability of girl = 0.5

n = number of couples in group = 42

since this is the case of binomial distribution so

mean = np = 42*0.5 = 21

standard deviation = = = 3.2404