Question

A pharmaceutical company has developed a test for a scarce disease that is present in 0.5% of the population. The test is 98% accurate in determining a positive result, and the chance of a false positive is 4%. What is the probability that someone who tests positive actually has the disease?

Answer 1

49% because there's 98% that the test is right BUT you only have 0.5% chance to actually have it, so 98×0.5=49

Answer 2

P(positive| has the disease)=0.96