1. The problem statement, all variables and given/known data People in a given community who have a certain disease is 0.005. A test is available to diagnose the disease. If a person has the disease, the probability that the test will produce a positive signal is 0.98. If a person does not have the disease, the probability that the test will produce a positive signal is 0.02. If a person tests positive on two successive tests, what is the probability that they have the disease? 2. Relevant equations I was assuming statistical independence, though the problem doesn't necessarily state that, so I was contemplating just multiplying the two probabilities. 3. The attempt at a solution I know from a previous part of the problem that the probability of having the disease, given a positive test result is .1976. I was going to multiply .1976*.1976 to get the answer for this question but according to the solution my TA provided that's wrong. His solution is .9235, which when I think about it, makes sense. But I don't know what he did to get to that value?