posted by scott .
A test designed to check for sickle-cell anemia has an 85% chance of detection in that, if a person has the disease, there is an 85% chance that the test will be positive. And, if the person does not have the disease, there is an 85% chance that the test will be negative. We also know that the proportion of people in the U.S. that has sickle-cell anemia is 0.00023.
Suppose an individual is drawn at random from the population of the U.S., and that the individual tests positive for sickle-cell anemia using the test described above. What is the probability that the individual has the disease?
Answer 0.15 0.0000766 0.85 0.0013 0.2499425