Acertain virus infects one in every 200 people. a test used to detect the virus in a person is positive 85% of the time if the person has the virus and 5% of the time if the person does not have the virus. (this 5% result is called a false positive.) a) find the probability that a person has the virus given that they have tested positive. round your answer to the nearest tenth of a percent and do not include a percent sign.

Our required probability is 0.07 i.e. 0.1.

Step-by-step explanation:

Let A be the event that "the person is infected".

Let B be the event that "the person tests positive".

Probability of person is positive if the person has the virus = 85%

Probability of person is positive if the person does not have the virus = 5%

P(B|A) = 0.85

So, P(A) =

P(B) is given by

So, We need to find P(A|B) which is given by

Hence, our required probability is 0.07 i.e. 0.1.

(1,-1) i hope this

step-by-step explanation: