1) Suppose that 1% of all people have a particular disease. A test for the disease is 99% accurate. This means that a person who has the disease has a 99% chance of testing positive for the disease, while a person who doesn't have the disease has a 99% chance of testing negative for the disease.
If a person tests positive for the disease, what is the chance (rounded to the nearest hundredth) that he or she actually has the disease?
Possible Answers:
0.99
0.40
0.50
0.45
None of the above