Posted by Betty on Tuesday, October 25, 2011 at 12:43pm.
Suppose that 3% of the population ha a certain disease. We have a test for the disease. 97% of those who actually have the disease will test positive. 12% of those who do not have the disease will also test positive. What is the probability that a randomly selected person has the disease and tests positive?

Probability  PsyDAG, Tuesday, October 25, 2011 at 3:12pm
Probability of both/events occurring is found by multiplying the probabilities of the individual events.
.03 * .97 = ?