[Nutsinatin]

Hopefully I have the correct answer, lets find out...

Firstly the 75% is a red herring as this man has a normal reading and that only applies to a high reading, so forget about that.
We know that 7% of men with a normal reading like this man do still have cancer.
We know that 1/14 men have prostate cancer, and that 7% of men with a normal reading also have cancer.
Therefore if we multiply the chance of him having cancer (1/14) by the chance of the test giving a false negative (7/100) we get 1/200 (0.5%) chance.
To summarise: (1/14) x (7/100) = 1/200 which is the same as 0.5/100 which is the same as 0.5%.

Hopefully someone will be along to confirm if I know what I'm talking about or if I'm leading you off down the wrong path and need to take this test too!