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Topic: Probabilities
Replies: 3   Last Post: Sep 5, 2012 7:08 PM

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kunzmilan@atlas.cz

Posts: 323
Registered: 2/21/06
Re: Probabilities
Posted: Mar 15, 2007 3:04 AM
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On Mar 13, 4:26 pm, Anonymous wrote:
> Hi all,
>
> I've got the following phrase:
>
> BABAAAAAABAAABBAAAAAABA
>
> I would like to calculate the conditional probability P(B|A).
> If I use a logical thought, I get:
>
> P(B|A) = the_number_of_AB / the_number_of_A = 4 / 17 = 0.23
>
> and if I use the formula P(B|A) = P(B inter A)/P(A) I get:
> P(B inter A) = 4 / (23-1)
> and P(A) = 17/23 then:
>
> P(B|A) = 4/22 * 23/17 = 0.25
>
> So I would like to know why the "logical thought" is wrong and if the
> result is right with the formula.
>
> Thanks a lot


Instead A and B, A.A.Markov counted vowels and consonants in a
Pushkine poem, and based his theory of chains on the matrix of these
counts.
kunzmilan



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