Refer to the table which summarizes the results of testing for a certain disease.
$$\begin{array} { l | c c }
& \text { Positive Test Result } & \text { Negative Test Result } \
\hline \text { Subject has the disease } & 87 & 6 \
\text { Subject does not have the disease } & 27 & 158
\end{array}$$
If one of the results is randomly selected, what is the probability that it is a false positive (test indicates the person has the disease when in fact they don't)? What does this probability suggest about the accuracy of the test?
A) 0.410; The probability of this error is high so the test is not very accurate.
B) 0.146; The probability of this error is high so the test is not very accurate.
C) 0.0216; The probability of this error is low so the test is fairly accurate.
D) 0.0971; The probability of this error is high so the test is not very accurate.

Question

Refer to the table which summarizes the results of testing for a certain disease. 
$$\begin{array} { l | c c } 
& \text { Positive Test Result } & \text { Negative Test Result } \
\hline \text { Subject has the disease } & 87 & 6 \
\text { Subject does not have the disease } & 27 & 158
\end{array}$$
 If one of the results is randomly selected, what is the probability that it is a false positive (test indicates the person has the disease when in fact they don't)? What does this probability suggest about the accuracy of the test?
A) 0.410; The probability of this error is high so the test is not very accurate.
B) 0.146; The probability of this error is high so the test is not very accurate.
C) 0.0216; The probability of this error is low so the test is fairly accurate.
D) 0.0971; The probability of this error is high so the test is not very accurate.

Quizplus · Accepted Answer

The probability of a false positive is calculated as the number of false positives (27) divided by the total number of tests (278), which equals 0.0971. This suggests that the probability of this error is relatively high, indicating the test may not be very accurate.

Refer to the Table Which Summarizes the Results of Testing