True Positives and False Positives
A screening test for colon cancer is administered to 1000 people with biopsy proven colon cancer and to 1000 people without colon cancer. The test results are positive for 250 people of proven cases and 100 of those without colon cancer.The screening test is now to be used on a population of 100,000 with a known prevalence rate of colon cancer of 80 per 100,000. Which of the following is the expected number of true positives and false positives in this population of 100,000 people?
True Positives  False positives
a. 20  9992
b. 20  89,928
c. 40  9992
d. 50  89,928
e. 60  9992
f. 60  89,928
g. 80  9992
h. 80  89,928
