BH Statistics **Homework for 2/24/00**

February 22, 2000

Design a ProbSim simulation and explain how you will its results to analyze this situation and question.

Assume there is a test for HIV virus that is 98% accurate (i.e., if someone has the HIV virus, the test will be positive 98% of the time, and if one does not have it, the test will be negative 98% of the time). Assume further that 0.5% of the population actually has the HIV virus. Imagine that you’ve taken this test and your doctor somberly informs you that you’ve tested positive. What is your probability of actually having HIV? (First, interpret this as a probabilistic situation. Then, answer the question.)