Diagnostic tests of medical conditions can have several types of results. The test result can be positive or negative, whether or not a patient has the condition. A positive test (+) indicates that the patient has the condition. A negative test () indicates that the patient does not have the condition. Remember, a positive test does not prove the patient has the condition. Additional medical work may be required. Consider a random sample of200 patients,some of whom have a medical condition and some of whom do not. Results of a new diagnostic test for a condition are shown.

Condition Present Condition Absent Row Total

Test Result 110 20 130

Test Result 21 49 70

Column Total 131 69 200