22 Aug
2002
22 Aug
'02
9:55 p.m.
[Tim]
... P(S|X) = (100+100)/200 = 1/2 and P(S|Y) = (500+500)/500 = 1/2
too by the same reasoning. P(not-S|X) and P(not-S|Y) are also 1/2 each.
So far, there's nothing a reasonable person can argue with.
And note that only an unreasonable person would argue that (100+100)/200 = 1, so don't even think about it <wink>. Of course those should have been P(S|X) = 100/(100+100) = 1/2 and P(S|Y) = 500/(500+500) = 1/2 There are probably other glitches like that. Work out the example yourself -- it's much easier to figure it out than to transcribe all the tedious numbers into a msg.