Question

In a large population, 69% 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?

Answer 1

0.991

Explanation:

Let Q be probability none of the 4 are vaccinated.

Let P be probability that at least 1 is vaccinated.

P = 1 - Q

Now if 69% are vaccinated, then 31% are not vaccinated.

Thus any given person has a probability of 0.31 of not being vaccinated.

Q = (0.31)^4 = 0.00924

P = 1 - 0.00924 = 0.991