Question

Refer to the accompanying table, which describes results from groups of 8 births from 8 different sets of parents. The random variable x represents the number of girls among 8 children. Find the mean and standard deviation for the number of girls in 8 births.

The mean is

μ=6.1

girl(s). (Round to one decimal place as needed.)

Table of numbers of girls and probabilities

Number of Girls x	P(x)
0	0.005
1	0.033
2	0.112
3	0.219
4	0.260
5	0.222
6	0.113
7	0.033
8	0.003

Answer 1

The random variable X represents the number of girls among 8 children and P(girl) = p = 0.5

Here, X ~ Binomial (n =8, p = 0.5)

Mean and standard deviation of a Binomial distribition are as follows,

Hence,

The mean = 4.0 girl(s)

The standard deviation = 1.4 girl(s)