Results 1 to 3 of 3

Math Help - [SOLVED] bayes' rule

  1. #1
    Newbie
    Joined
    Oct 2008
    Posts
    16

    [SOLVED] bayes' rule

    If I have e.g. P(A|B) is 0.9 and P(not A|not B) = 0.9 then how do I find P(A|not b) and P(not A|B)? Also, how do I find the P(A)?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Flow Master
    mr fantastic's Avatar
    Joined
    Dec 2007
    From
    Zeitgeist
    Posts
    16,948
    Thanks
    5
    Quote Originally Posted by joop View Post
    If I have e.g. P(A|B) is 0.9 and P(not A|not B) = 0.9 then how do I find P(A|not b) and P(not A|B)? Also, how do I find the P(A)?
    Draw a tree diagram. The first two branches are B and B'. Then from each of these branches you have the two branches A and A'.

    It should then be clear that Pr(A | B') = 0.1 and Pr(A' | B) = 0.1.

    There's not enough information to calculate a numerical value of Pr(A).
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Oct 2008
    Posts
    16
    I solved for P(A) by drawing a diagram (P(B) was given to us). Thanks a lot though.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Application of Bayes rule / Girsanov density
    Posted in the Advanced Statistics Forum
    Replies: 6
    Last Post: June 23rd 2011, 07:37 AM
  2. Bayes Rule probability problem.
    Posted in the Statistics Forum
    Replies: 5
    Last Post: May 9th 2011, 10:58 AM
  3. Bayes Rule applied to Political Business Cycle Model
    Posted in the Advanced Statistics Forum
    Replies: 0
    Last Post: November 8th 2009, 06:21 PM
  4. Bayes rule solution check
    Posted in the Advanced Statistics Forum
    Replies: 4
    Last Post: February 3rd 2008, 03:29 PM
  5. Bayes Rule?
    Posted in the Advanced Statistics Forum
    Replies: 2
    Last Post: January 26th 2008, 04:26 PM

Search Tags


/mathhelpforum @mathhelpforum