Question

Acme Manufacturing Company requires all of its 4750 employees to take a drug

test. Suppose 4% of the employees actually use drugs (although the company does not know this number). The drug test is 98% accurate.

1. How many of Acme’s employees use drugs?
2. How many of the employees who use drugs get a positive test result?
3. How many of the employees who do not use drugs get a positive test result?
4. Of the employees who get a positive test result, how many of them use

drugs? Convert this to a percentage: What percent of people who get a positive result actually use drugs?

5. State a conclusion about the accuracy of the test.

Answer 1

	Positive Result	Negative	Total
Use Drugs	186.2	3.8	190
Not Use Drugs	91.2	4468.8	4560
Total	277.4	4472.6	4750

1)

Here Total Employee = 4750

Employee who use drugs = 4750 *0.04 = 190

2)

Since test is 98% accurate

Positive among this will be = 0.98 * 190 = 186.2

3)

employees who do not use drugs = 4750 -190 = 4560

get a positive test result = 4560 *0.02 = 91.2

4)

employees who get a positive test result, how many of them use

drugs = 186.2 (from the table above)

5)

percent of people who get a positive result actually use drugs = 186.2 / 277.4 = 67.12%

Please revert back in case of any doubt.