Replies to post #16980 on Biotech Values

[io_io]

"False Positives"

To answer your question, the chances are rather small that she's sick.

I am going to guess 2% .......... if you tested every single one of the 1,000 patients, you would get 5% = 50 wrong answers.

So it looks like it's 1/50 = 2%

I could come up with a formula, given time, but this is one of the problems with diagnostic tools - false positives.

Of course false negatives would be much rarer - but potentially much more serious.