6. (9 pts) A girl is concerned she might have a disease that affects 1% of the population. Luckily, a drug-store test is available. The test has a false-positive rate of 3% and a false-negative rate of 1% (a false positive is when a person doesn't have the disease, but the test result is positive). (a) What is the probability of a positive test result? (b) The girl takes the test, and it returns positive. Given this information, what is the proba- bility that she has the disease? (c) The girl is aware that the test is imperfect, so she decides to take a second test. It also returns positive. Given the results of both tests, what is the probability that she has the dis- ease? You may assume that the two test results are conditionally independent given her disease status