00:01
The probability that a child is a boy is 0 .51.
00:04
We're looking at a family of 5.
00:06
So here we have 5 children.
00:08
The probability of each one being a boy is 0 .51.
00:13
So we do have a binomial distribution here.
00:18
So each child is independent, and each one has a 0 .51 chance of being a boy, 0 .49 of being a girl.
00:28
And we're going to use the binomial formula to answer this question.
00:31
So the binomial formula is that the probability of exactly x being boys is equal to n choose x, p to the power of x, 1 minus p to the n minus x.
00:46
So these three terms multiply together give you the probability of x of the children being boys.
00:54
What we're looking at here is the probability that none of them are boys.
00:59
So that's like having five crosses in a row.
01:07
So this term is going to be 0 .51 to the power of 0 ,0 because none of them are boys...