Suppose of the population has a disease. If a person has the disease the test is positive with probability ; if not, the test is (falsely) positive with probability . What is the probability that a tested person has the disease given a positive test?
Tap an option to check your answer.
Checking your account…
Suppose 1/10 of the population has a disease. If a person has the disease the test is positive with probability 8/10; if not, the test is (falsely) positive with probability 2/10. What is the probability that a tested person has the disease given a positive test? (A) 1 (B) 9/13 (C) 4/13 (D) 7/13
Probability and Bayes' theorem has come up 190 times in 7 exams since 2004.
This question is on Total probability and Bayes' theorem, part of Probability and Bayes' theorem in Statistics.
Reversing a conditional probability and updating beliefs from evidence.
TestStop has 22 past-paper questions on this subtopic.
Question from the DSE 2017 paper. Solutions are TestStop's own. Not affiliated with or endorsed by any examination authority.