Find the probability that when a couple has three ​children, at least one of them is a boy. ​(Assume that boys and girls are equally​ likely.)

Respuesta :

Answer:

The probability that at least 1 of the 3 children is a boy is 0.875.

Step-by-step explanation:

The probability of a baby born being a girl or a boy is same, i.e.

P (G) = P (B) = 0.50.

A couple has 3 children.

Let X = number of boys.

The random variable X follows a Binomial distribution. The probability of a Binomial distribution is computed using the formula:

[tex]P(X=x)={n\choose x}p^{x}(1-p)^{n-x};\ x=0, 1, 2...[/tex]

Compute the probability that at least 1 of the 3 children is a boy as follows:

P (At least 1 boy) = 1 - P (No boys)

              P (X ≥ 1) = 1 - P (X = 0)

                            [tex]=1-{3\choose 0}(0.50)^{0}(1-0.50)^{3-0}\\=1-(1\times1\times0.125)\\=1-0.125\\=0.875[/tex]

Thus, the probability that at least 1 of the 3 children is a boy is 0.875.