Answer:
The required probability is 0.6053
Step-by-step explanation:
Consider the provided information.
Among 148 subjects with positive test results, there are 28 false positive results.
That means the true positive results are: 148-28=120
Among 156 negative results, there are 4 false negative results.
That means the positive results are 156-4=152
Positive Negative Total
Use marijuana F negative 120 4 124
Not use marijuana F positive 28 152 180
Total 148 156 304
The probability that the subject tested negative or did not use marijuana.
P(Negative∪ not use marijuana)=[P(Negative)+P(Not use marijuana)-P(negative ∩ not use marijuana)]
P(Negative∪ not use marijuana) =
P(Negative∪ not use marijuana) =
P(Negative∪ not use marijuana) =
P(Negative∪ not use marijuana) ≈
Hence, the required probability is 0.6053