Subject has the disease positive result 120 negative result

Subject has the disease, positive result 120; negative result 4; subject does not have the disease, positive result 13, negative result 172. If one of the results is randomly selected, what is the probability that it is a false negative (test indicates the person does not have the disease when in fact they do)? What does this probability suggest about the accuracy of the test?

Solution

to determine the false negative we will take in account for subject does not have the disease

positiv = 13, negative = 172

hence probability for false negative = 172/185 = 0.929

having high probability means that this has a high accuracy.