question archive Suppose that you are testing for a toxin in the water and you know the following facts
Suppose that you are testing for a toxin in the water and you know the following facts
Subject:StatisticsPrice: Bought3
Suppose that you are testing for a toxin in the water and you know the following facts.
1)The toxin will be in the water with probability 0.07.
2)The false positive rate (the conditional probability that the test returns positive given that the toxin is not present) is unknown, call it x.
3)The false negative rate is 0, so when the toxin is present the test always returns positive.
What does the false positive rate have to be in order for the precision (the probability that the toxin is present given a positive test) to be 0.6? Denote the event that a test returns positive as T and the event that the toxin is present as C. You must solve for x where 0.6 = P(C|T)
