Mathematics desk
< January 22	<< Dec \| January \| Feb >>	January 24 >

Welcome to the Wikipedia Mathematics Reference Desk Archives
The page you are currently viewing is an archive page. While you can leave answers for any questions shown below, please ask new questions on one of the current reference desk pages.

January 23

Related probabilities

If 15% of drivers involved in automobile accidents are not wearing a seat belt at the time of their crash, yet they account for 27% of accident fatalities amongst all drivers, then we can compute that an unrestrained driver is ( 0.27 / 0.73 ) / ( 0.15 / 0.85 ) = 2.1 times more likely to die if they have an accident, right? What is this sort of calculation called, and do we have an article on it? -- ToE 00:27, 23 January 2012 (UTC)[reply]

conditional probability. Bo Jacoby (talk) 08:03, 23 January 2012 (UTC).[reply]

Thanks; that's exactly what I was looking for. Does this particular manipulation

{\frac {P(A|\neg B)}{P(A|B)}}={\frac {P(\neg B|A)/P(\neg B)}{P(B|A)/P(B)}}

(easily derived from Bayes' theorem) get used enough in some circles to be given its own name. -- ToE 01:03, 24 January 2012 (UTC)[reply]

With some rearrangement of the terms this becomes Bayes' rule. (The roles of A and B are interchanged in that page). -- Meni Rosenfeld (talk) 16:21, 24 January 2012 (UTC)[reply]

Not in my circles. Bo Jacoby (talk) 12:28, 24 January 2012 (UTC).[reply]