Consider two medical tests, A and B, for a virus. Test A is 95% effective at recog- nizing the virus when it is present, but has a 10% false positive rate (indicating that the virus is present, when it is not). Test B is 90% effective at recognizing the virus, but has a 5% false positive rate. The two tests use independent methods of identifying the virus. The virus is carried by 1% of all people. Say that a person is tested for the virus using only one of the tests, and that test comes back positive for carrying the virus. If this is test B, then it is more indicative than test A, that this person has the virus. Hint: The information in the problem can be expressed as follows: P(V ) = 0.01 P(AV ) = 0.95 P(A|-V ) = 0.10 P(B|V) = 0.90 P(B|-V ) = 0.05 To answer the question you have to find out which one is bigger, P(VIA) or P(V|B).