A recent study conducted by a health statistics center found that 27​% of households in a certain country had no landline service. This raises concerns about the accuracy of certain​ surveys, as they depend on​ random-digit dialing to households via landlines. Pick three households from this country at random. Complete parts​ a) through​ c) belowa) what is the probability that all five of them have a landline?
b) what is the probability that at least one of them does not have a landline?
c) what is the probability that at least one of them does have a landline?

Respuesta :

Answer:

The probability that all five of them have a landline is 20.73%.

The probability that at least one of them does not have a landline 79.27%.

The probability that at least one of them does have a landline is 99.86%.

Step-by-step explanation:

Consider the provided information.

A recent study conducted by a health statistics center found that 27​% of households in a certain country had no landline service.

let p is the probability that they have land line p=0.73

let q is the probability that they have no land line: q=0.27

(a) What is the probability that all five of them have a landline?

[tex]P(X=x)=^n{C_{x}}p^xq^{n-x}[/tex]

[tex]P(X=5)=^5{C_{5}}(0.73)^5(0.27)^{5-5}[/tex]

[tex]P(X=5)=0.2073071593[/tex]

The probability that all five of them have a landline is 20.73%

(b) What is the probability that at least one of them does not have a landline?

P(at least one no landline) = 1-P(All have landline)

P(at least one no landline) = 1-0.2073

P(at least one no landline) = 0.7927

The probability that at least one of them does not have a landline 79.27%.

(c) What is the probability that at least one of them does have a landline?

P(at least one have landline) = 1-P(no one have landline)

P(at least one have landline) = [tex]1-0.27^5[/tex]

P(at least one have landline) = [tex]0.9986[/tex]

The probability that at least one of them does have a landline is 99.86%.