11. MRIs An article in The American Journal of Sports Medicine studied the accuracy of MRIs (magnetic resonance imaging) in detecting cartilage tears at two sites in the knees of 35 patients. The 233570 examinations produced the classifications shown in the table.8 Actual tears were confirmed by arthroscopic surgical examination.

a. What is the probability that a site selected at random has a tear and has been identified as a tear by MRI?

b. What is the probability that a site selected at random has no tear and has been identified as having a tear?

c. What is the probability that a site selected at random has a tear and has not been identified by MRI?

d. What is the probability of a positive MRI, given that there is a tear?

e. What is the probability of a false negative—that is, a negative MRI, given that there is a tear?

Transcribed Image Text:

Tears No Tears Total MRI Positive MRI Negative Total 27 0 27 4 39 43 31 39 70