Suppose the following contingency table applies when a physi

Suppose the following contingency table applies when a physician recommends that a patient undergo a treadmill stress test to evaluate the condition of the heart. What is the probability that the patient either is not normal or will test as not normal?

Solution

Prob for patient not normal = 0.05+0.15 = 0.20

Prob for test as not normal = 0.01+0.15 = 0.16

Prob that the patient is either not normal or will test as not normal

= P(A) +P(B)-P(AB)

=0.20+0.16-0.15

= 0.21