Subject has the disease positive test result : 87 negative test result : 9 Subje
ID: 3066803 • Letter: S
Question
Subject has the disease
positive test result : 87
negative test result : 9
Subject does not have disease
positive test result: 27
negative test result: 310
Assume that selections are mde without replacement. Two subjects are randomly selected. What is the probability that both of the selected subjects have the disease along with a positive test result?
One test subject is randomly selected and tested for the disease. What is the probability the subject has the disease given that the test result is negative ?
Explanation / Answer
1) probability that both of the selected subjects have the disease along with a positive test result
=(87/433)*(86/432) =0.04
2) probability the subject has the disease given that the test result is negative =9/319=0.0282
test positive test negative total have disease 87 9 96 not have disease 27 310 337 total 114 319 433