A researcher wishes to conduct a study of the color preferences of new car buyers. Suppose that 40% of this population prefers the color red. If 14 buyers are randomly selected, what is the probability that exactly 2 buyers would prefer red

Respuesta :

Answer:

The probability that exactly 2 buyers would prefer red car is 0.0317.

Step-by-step explanation:

Let the random variable X represent the number of buyers would prefer red car.

The probability of the random variable X is, p = 0.40.

A random sample of n = 14 buyers are selected.

The event of a buyer preferring a red car is independent of the other buyers.

The random variable X thus follows a Binomial distribution with parameters n = 14 and p = 0.40.

The probability mass function of X is:

[tex]P(X=x)={14\choose x}(0.40)^{x}(1-0.40)^{14-x};\ x=0,1,2,3...[/tex]

Compute the  probability that exactly 2 buyers would prefer red car as follows:

[tex]P(X=2)={14\choose 2}(0.40)^{2}(1-0.40)^{14-2}[/tex]

                [tex]=91\times 0.16\times 0.0021768\\=0.031694208\\\approx 0.0317[/tex]

Thus, the probability that exactly 2 buyers would prefer red car is 0.0317.