For the next two questions consider a medical test with a false positive rate of
ID: 3235685 • Letter: F
Question
For the next two questions consider a medical test with a false positive rate of 5% and a false negative rate of 5%. The frequency of the condition in people who take this test is 2% What value is closest to the percentage of people who test "positive" who are actually negative for the condition? (A) 70% (B) 75% (C) 80% (D) 85% (E) 90% What value is closest to the percentage of people who test "negative" who are genuinely negative for the condition? (A) 99.95% (B) 99.96% (C) 99.97% (D) 99.98% (E) 99.99%Explanation / Answer
(a) 4.9/100 = 4.9%
(b) 93.1/100 = 93.1%
Positive Negative Total Disease 2 - 0.1 = 1.9 5% of 2 = 0.1 2 No Disease 5% of 98 = 4.9 98 - 4.9 = 93.1 98 Total 6.8 93.2 100