Refer to the table which summarizes the results of testing for a certain disease.
$\begin{array}{l|cc}
&\text { Positive Test Result}&\text { Negative Test Result }\
\hline \text { Subject has the disease } & 82 & 10 \
\text { Subject does not have the disease } & 25 & 326
\end{array}$

A 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?
A) 0.109
B) 0.208
C) 0.03
D) 0.97

Question

Refer to the table which summarizes the results of testing for a certain disease. 
$\begin{array}{l|cc}
&\text {  Positive Test Result}&\text {  Negative Test Result }\
\hline \text { Subject has the disease } & 82 & 10 \
\text { Subject does not have the disease } & 25 & 326
\end{array}$

A 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?
A) 0.109
B) 0.208
C) 0.03
D) 0.97

Quizplus · Accepted Answer

The probability that the subject has the disease given a negative test result is calculated as the number of true negatives (10) divided by the total number of negative test results (10 + 326), which is 10/336 = 0.03.

Refer to the Table Which Summarizes the Results of Testing