In a large population, 54% of the people have been vaccinated. If 4 people are randomly selected, what is the probability that at least one of them has been vaccinated? Round your answer to three decimal places.

Respuesta :

Answer:

[tex] P(X \geq 1) = 1- P(X<1) =1-P(X=0)[/tex]

We can use the probability mass function and we have this probability:

[tex]P(X=0)=(4C0)(0.54)^0 (1-0.54)^{4-0}=0.0448[/tex]

And replacing we got:

[tex] P(X \geq 1) =1- 0.0448 = 0.955[/tex]

Step-by-step explanation:

Let X the random variable of interest "number of people vaccinated", on this case we now that:

[tex]X \sim Binom(n=4, p=0.54)[/tex]

The probability mass function for the Binomial distribution is given as:

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

Where (nCx) means combinatory and it's given by this formula:

[tex]nCx=\frac{n!}{(n-x)! x!}[/tex]

And we want to find this probability:

[tex] P(X \geq 1) = 1- P(X<1) =1-P(X=0)[/tex]

We can use the probability mass function and we have this probability:

[tex]P(X=0)=(4C0)(0.54)^0 (1-0.54)^{4-0}=0.0448[/tex]

And replacing we got:

[tex] P(X \geq 1) =1- 0.0448 = 0.955[/tex]