brain sizes: Einstein's and women's
thatjetnospam at yahoo.com
Fri Jul 19 01:19:37 EST 2002
Parse Tree wrote:
> "mat" <mats_trash at hotmail.com> wrote in message
> news:43525ce3.0207180723.642fd8f9 at posting.google.com...
> > >
> > > If you're asked a question which has four multiple choice answers, and
> > > haven't got a clue what the answer is, what is the probability of
> getting a
> > > correct answer? Since you have once chance in four of getting the right
> > > answer, your probability is 0.25. If you guess on two questions, your
> > > probability is .5, and three it's .75, and four, it's 1.0.
> > So you are certain to get a correct answer if you guess on four
> > questions? and you claim to understand probability?!
> > P(one questions correct given 4 choices and if guessing) = 0.25
> > P(two questions correct) = 0.25 x 0.25 = 0.0625
> > P(three questions correct) = 0.25 x 0.25 x 0.25 = 0.015625
> > .
> > .
> > .
> > P(n questions correct) = 0.25^n
> Actually, he was talking about getting only one correct, as far as I can
> tell. He's still wrong though.
He came to the conclusion that a negative number of people go the answer
right without guessing. I kid you not!
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