Fine tuning argument assessed

[Whateverist]

Yeah, here's another one: http://en.wikipedia.org/wiki/Sally_Clark...l_evidence

Close, but the answer is actually 1/3 (you may have misread that the background rate was 0.5%, not 1%)

Best way to think about it without doing the maths is that if you tested 200 people, 1 of which is actually a drug taker, the most likely outcome would be:
2 false positives.
1 true positive.

Therefore 1/3 positives are true ones.

Ha! True enough I guess. I was thinking in terms of one True positive to two false, hence one in two. But on reflection I like your answer.

The probability is on Tony's side but the odds favor Jacob.