Use the following results from a test for marijuana use, which is provided by a
ID: 3293994 • Letter: U
Question
Use the following results from a test for marijuana use, which is provided by a certain drug testing company. Among 144
subjects with positive test results, there are
27
false positive results; among
158
negative results, there are
4
false negative results. If one of the test subjects is randomly selected, find the probability that the subject tested negative or did not use marijuana. (Hint: Construct a table.)The probability that a randomly selected subject tested negative or did not use marijuana is
nothing.
(Do not round until the final answer. Then round to three decimal places as needed.)
Explanation / Answer
P(Subject tested negative or did not use marijuana)
= (27+158)/(144+158)
= 185/302
= 0.613