In a population 7% of people are infected by a virus.
A screening test for the virus shows positive (for infection) or negative.
The correctly shows positive for 99% of cases of infected people.
The test for the virus incorrectly shows positive for 3% of cases of uninfected people.
a) What is the probability that the test shows positive when used on any person?
b) What is the probability that someone is really infected when the test shows positive?
c) What is the probability that someone is really infected when the test shows negative?
Mathbot Says...
I wasn't able to parse your question, but the HE.NET team is hard at work making me smarter.