Diagnostic tests of medical conditions can have several types of results. The te
ID: 3328603 • Letter: D
Question
Diagnostic tests of medical conditions can have several types of results. The test result can be positive or negative, whether or mot 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 of 200 patients, some of whome have a medical condition and some of whom do not. Results of a new diagnostic test for the condition are shown Test Result 16 54 0 Assume the sample is representative of the entire population. Far a person selected st random, compute the tilowing probuabilies. Enter your answers fractions.) is representative of the entire population. For a person selected at a)P+I condition present); this is known as the senseivity of a test (b) R- I condition present); this is known gs the falise-negaive rate. (c) P-I condition absent); this is known as the specifloty of a test )P+I condsition absent); this is known as the false-postive rate e) Pcondition present and +) this is the predictive value of the test. 054 ) condition present and-). Noed Help? HANNSpreeExplanation / Answer
Note that we have to enter the answers in form of fractions here as given in the problem
a) Using bayes theorem the probability here is computed as:
P( + | condition present ) = n( + , condition present ) / n( present ) = 107 / 123
b) Using bayes theorem the probability here is computed as:
P( - | condition present ) = n( - , condition present ) / n( present ) = 16 / 123
c) Using bayes theorem the probability here is computed as:
P( - | condition absent ) = n( - , condition absent ) / n( absent ) = 54 / 77
d) Using bayes theorem the probability here is computed as:
P( + | condition absent ) = n( + , condition absent ) / n( absent ) = 23 / 77
e) P ( condition present and + )
= n ( condition present , + ) / Total frequency
= 107 / 200