Consider a population in which 80% of males and 60% of females are employed. In this population, 55% of individuals are females. If I pick five persons at random from this population, what is the probability that no more than one of those chosen is not employed?

Respuesta :

Answer:

The probability that no more than 1 person is not employed is 0.5077.

Step-by-step explanation:

Let's denote the events as:

E = a person is employed

M = a person is male

F = a person is a female.

Given:

P (E | M) = 0.80

P (E | F) = 0.60

P (F) = 0.55

P (M) = 1 - P (F) = 1 - 0.55 = 0.45

Compute the probability that a randomly selected person is employed as follows

P (E) = P (E | M) × P (M) + P (E | F) × P (F)

       [tex]=(0.80\times0.45)+(0.60\times0.55)\\=0.69[/tex]

Then the probability that a randomly selected person is not employed is,

P (E') = 1 - P (E) = 1 - 0.69 = 0.31

Now let's assume X = number of employees that are not employed.

The sample selected is of size, n = 5.

Then the random variable [tex]X\sim Bin(n=5, p=0.31)[/tex]

The probability function of Binomial distribution is:

[tex]P(X=x)={n\choose x}p^{x}(1-p)^{n-x}[/tex]

Compute the probability that no more than 1 person is not employed as follows:

P (X ≤ 1) = P (X = 0) - P (X = 1)

             [tex]={5\choose 0}(0.31)^{0}(1-0.31)^{5-0}+{5\choose 1}(0.31)^{1}(1-0.31)^{5-1}\\=0.1564-0.3513\\=0.5077[/tex]

Thus, the probability that no more than 1 person is not employed is 0.5077.