how to solve this epidemiology problem

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: a 55 yr old man visits his gp with urinary infrequency.o/e there is a 1 cm nodule in the prostrate.the pros.spec.antigen test is ordered.normally psa greater than 4ng/ml is abnormal.the test is 80% sensitive and 90% specific.a recently published epidemiological article found that 10% of the men of this age has prostrate cancer.the result on the patient is 7ng/ml.what is the best estimate of the likelyhood this man has prostrate cancer.
A 13%
B 25%
C 36%
D 47%
E 58%
F 69%
G 72%
H 81%

thanks in advance

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