Polygraph Test. Suppose that a polygraph is 85% accurate (it will correctly detect 85% of people who are lying and it will correctly detect 85% of people who are telling the truth). The 2000 employees of a company are given a polygraph test during which they are asked whether they use drugs. All of them deny drug use, when, in fact, 1% of the employees actually use drugs. Assume that anyone whom the polygraph operator finds untruthful is accused of lying. a. Verify that the entries in the table below follow from the given information. Explain each entry.

Users/ Non-users /Total

Test Finds Employee Lying: 17 /297 /314

Test Finds Employee Truthful: 3 /1683 / 1686

Total: 20 /1980 /2000

b. How many employees are accused of lying? Of these, how many were actually lying and how many were telling the truth? What percentage of those accused of lying were falsely accused?

c. How many employees are found truthful? Of these, how many were actually truthful? What percentage of those found truthful really were truthful?