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Unformatted text preview: cancer, doctors often perform a test that measures the level of the PSA protein (prostate speciﬁc antigen) that is produced only by the prostate gland. Although higher PSA levels are indicative of cancer, the rest is notoriously unreliable. Indeed, the probability that a noncancerous man will have an elevated PSA level is approximately . 135, with this probability increasing to approximately . 268 if the man does have can-cer. If, based on other factors, a physician is 70 percent certain that a male has prostate cancer, what is the conditional probability that he has the cancer given that (a) the test indicates an elevated PSA level; (b) the test does not indicate an elevated PSA level? Repeat the preceding, this time assuming that the physician initially believes there is a 30 percent chance the man has prostate cancer. 2...
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- Summer '08
- Probability theory, Prostate cancer, elevated PSA level, Prostate-specific antigen