So i multiplied 1/14 with 7 to try and get the percentage of those that have false negatives and prostate cancer i got 0.5 which is wrong, the correct answer is D. How do you get the answer?
Approximately 1 in 14 men over the age of 50 has prostate cancer. The level of ‘prostate specific antigen’ (PSA) is used as a preliminary screening test for prostate cancer.
7% of men with prostate cancer do not have a high level of PSA. These results are known as ‘false negatives’.
75% of those men with a high level of PSA do not have cancer. These results are known as ‘false positives’.
If a man over 50 has a normal level of PSA, what are the chances that he has prostate cancer?
A. 7%
B. 25%
C. 5%
D. 0.7%
E. 0.5%