Question

Use the table below to find the probability.

	Positive Test Result	Negative Test Result
Subject Uses Drugs	44 (True Positive)	6 (False Negative)
Subject is Not a Drug User	90 (False Positive)	860 (True Negative)

Find . (Round to 4 decimals)

Answer 1

	positive test	negative test	total
subject used drugs	44 true positive	6 false negative	50
subject is not drug user	90 false negative	860 true negative	950
total	134	866	1000

Probability that the subject had a positive test result or does not use drugs P(positive or doesn't use drugs)

=P(positive)+P(doesn't use drugs)-P(positive and doesn't use drugs)

P(negative result or doesn't use drugs)

=P(negative)+P(doesn't use drugs)-P(negative and doesn't use drugs)