It is known that a rare disease, K, is present only in 0.2% of the population. Performance of the test by a physician's diagnostic test for the presence or absence of the disease K is given in Table, where R+ denotes the positive test result, and R- denotes the negative result. Also, Kc denotes absence of the disease.
Table
|
|
R+
|
R-
|
K
|
0.98
|
0.02
|
Kc
|
0.01
|
0.99
|
(a) What is the probability that a patient has the disease, if the test result is positive?
(b) What is the probability that a patient has the disease, if the test result is negative?