The probability of a randomly selected adult in one country being infected with a certain virus is 0.002. in tests for the virus, blood samples from 30 people are combined. what is the probability that the combined sample tests positive for the virus? is it unlikely for such a combined sample to test positive? note that the combined sample tests positive if at least one person has the virus.

The probability that the combined sample tests positive for the virus is 0.058 approximately.

Step-by-step explanation:

Consider the provided information.

It is given that the probability of infected with a certain virus is 0.002.

This can be written as:  

p = probability of infected with virus = 0.002.

The probability of not infected with virus is:

q = probability of not infected with virus = 1 - p = 0.998

Blood samples from 30 people are combined.

Therefore the value of n is 30.

It is given that the combined sample tests positive if at least one person has the virus.

This can be written as:

Where x is the number of people infected with virus.

0.058 means that the probability is 5% that the combined test will be positive.

So, it is not unlikely for the combined sample tests positive for the virus.

4

step-by-step explanation:

6 (donuts) divided by 3 is 2.

so 2/3 means 2 times 2, which is 4/6.

you get two and your friend gets four.