A screening test was performed on 250 people to detect Factor X, which is associated with Disease Y. The results were compared to previous definitive diagnoses for Disease Y. Of those who tested positive for Factor X, 40 out of 100 had Disease Y, giving the test a positive predictive value of 40%.

1. A screening examination was performed on 250 persons for Factor X, which is found in disease
Y. A definitive diagnosis for disease Y among the 250 persons had been obtained previously.
The results are charted below:
RESULTS OF DIAGNOSIS
TEST RESULTS Disease Y Present Disease Y Absent
Positive for Factor X 40 60
Negative for Factor X 10 140
5) The positive predictive value of this test is:
A. 40%
B. 70%
C. 7%
D. 80%
Solution
5) The positive predictive value of this test is:
A. 40%
B. 70%
C. 7%
D. 80%