Imagine a Base Rate of 1 Percent for a Disease

Multiple Choice

Imagine a base rate of 1 percent for a disease, a false positive rate of 10 percent, and a sensitivity rate of 90 percent for the screening test for the disease. Using natural frequencies, which of the following is the closest estimate of the conditional probability that a person actually has the disease given a positive test result?

A) 8 percent
B) 10 percent
C) 16 percent
D) 20 percent