STAT 400 Final: STAT400 BOYLE-M FALL2003 0101 FINAL SOL

• School: University of Maryland
• Department: Statistics and Probability
• Course: STAT 400
• Professor: All

Document Summary

Prob(winning at least once) = 1 prob(not winning at all) . 870 . 130: (25 points) according to some studies, a polygraph test will correctly identify a liar in 88% of the cases and will correctly identify a truth-teller in 86% of the cases. Now suppose the test is used on a population of (largely innocent) people, for which the probability of lying on the test is . 01. Let l denote the event that the person is lying. Let b denote the event that the polygraph says the person is lying. The problem requires us to compute the conditional probability of l given b: P (l b) + p (l b) P (l)p (b|l) + p (l )p (b|l ) (. 01)(. 88) + (. 99)(1 . 86) . 0597 (. 01)(. 88) Typeset by ams-tex: a child of two carriers of a certain recessive disease will with probability . 25 have the disease.