"CowPunk" a écrit dans le message de news:
...

If the probability of a false positive is .01 then the probability of
both
A and B samples receiving a false positives is .01 * .01 = .0001. I
think

No I said 99% accuracy. Errors could be based on mishandling sample,
contamination, etc.... I just don't believe that a lab is 99.9%
accurate in their work.


We have 12000 test and 1% have a wrong result. 1% out of 12000 = 120.
Yes


380 Positive * 1% = 3.8 ( so 3.8 out of 380 are clean guys called
cheaters)

So now you are applying 1% again.
Which means you are calculating based 0.1% accuracy. 1%x1%

Of course no. The figure 380 of positive result is your, not the result of
some 1%


Where we are diverging is you are applying 1% to the positives, while I
am applying 1%
to the total # of tests. IMHO, Accuracy of a test applies to the total
# of tests performed.