Question

Approximately 18% of the population of California is 70 years or older. In a random sample of 4, what is the provability for 3 of these people to be older than 70 years old.\

Answer 1

The correct response will be "0.01913".

Explanation:

According to the question,

p - P(70 years or older)

= 0.18

n = 4

X = no. of individuals who are older than 70 years

Now,

∴
`P(X=r)=n_C_r \ p^r(1-p)^(n-r)`

∴
`P(X=3)=4_C_3(0.18)^3(1-0.18)^(4-3)`

`=4* (0.18)^3(0.82)^1`

`=0.01913`