Question

It has been found out that the probability that a child is a male in family is 0.4. In a family of 6 children, what is the probability that; i. exactly 5 are boys ? ii. at least 4 are boys ? iii. all boys

Answer 1

Formula (if you don't use the binomial probability table):

P(x) = (nCx)(p^x)[q^(n-x)]

Values:
n = 6
p = 0.4
q = 1 - p = 1 - 0.4 = 0.6

i. Find P(5)

ii. Find P(4), P(5), and P(6). Add together for your total probability.

iii. I'll let you try this one on your own.

I hope this will help get you started.

Answer 2

.036864

Answer 3

.0781