The following situation is from a Marilyn vos Savant column in the Sunday Parade. Is she right or is she wrong? Be sure you can defend your answer!
"Suppose it is assumed that about 5% of the general population uses drugs. Assume further that you employ a drug test that is 95% accurate*.
A person is selected at random and given the test. The test is positive. What does such a result suggest? Would you conclude that the individual is highly likely to be a drug user?"
Here is Marilyns answer: "Given the conditions, once a person has tested positive, you may as well flip a coin to determine whether he or she is a drug user. The chances are 50-50."
Work on this project in pairs. Be ready to do two things by tomorrows class (3/2/00):
(2) Present your reasoning and solution in class for discussion. Aim to give a clear explanation of your thinking so that others can understand it.