Questions: Refer to the sample data for pre-employment drug screening shown below. If one of the subjects is randomly selected, what is the probability that the test result is a false positive? Who would suffer from a false positive result? Why? Pre-Employment Drug Screening Results Positive test result Negative test result ---------------------------------------------------------------------- Drug Use Is Indicated 37 4 Subject Is Not a Drug User 18 36 The probability of a false positive test result is . (Round to three decimal places as needed.)

Solution Steps

To find the probability of a false positive, we need to determine the number of false positive cases and divide it by the total number of subjects. A false positive occurs when the test indicates drug use, but the subject is not a drug user. In this case, the number of false positives is 18. The total number of subjects is the sum of all the subjects in the table.

A false positive occurs when the test result is positive, but the subject is not a drug user. From the data, the number of false positives is 18.

The total number of subjects is the sum of all the entries in the table: \[ 37 + 4 + 18 + 36 = 95 \]

The probability of a false positive is given by the ratio of false positives to the total number of subjects: \[ \frac{18}{95} \approx 0.1895 \]

Final Answer