1. CPK and SGOT tests are used in the diagnosis of myocardialinfarction (MI). When the CPK test is given to a patient who doesnot have a MI, the probability of a negative finding (i.e. itsspecificity) is 0.6. The probability that the SGOT test will benegative for a non-MI patient is 0.7. When both tests are given toa non-MI patient the probability that at least one is negative is0.9. For a non-MI patient who has both tests:
- What is the probability that both tests are negative?
- What is the probability that both tests are positive?
Hints: (1) Answer is not 0.12 -- testsare not to be assumed to be independent.
          (2)Using 2-by-2 table to structure your calculations can help.
- What is the probability that at least one test ispositive?
