Question

Refer to the table which summarizes the results of testing for a certain disease. A test subject is randomly selected and tested for the disease. What is the probability the subject has the disease given that the test result is negative. Round to three decimal places as needed.Positive Test ResultNegative Test ResultSubject has the disease879Subject does not have the disease27312

Answer 1

Answer: 0.021

First, we will find the total number of results by adding up all the subject results in the table:

`87+9+27+312=435`

Now, we know there are 435 total results. We are asked to find the probability that the subject has the disease given that the test result is negative.

Looking at the table, we can see that the number of subjects that has the disease despite having negative results is 9. We will then divide these results by the total number of subject results to find the probability being asked:

`P=(9)/(435)=0.020689\approx0.021`

With this, we know that the probability of the subject having the disease given the results is negative is 0.021.