Results 1 to 3 of 3

Math Help - question on probability and bayes

  1. #1
    Junior Member
    Joined
    Jan 2009
    Posts
    57

    question on probability and bayes

    Let A be the event that a patient has cancer. In the course of a hospital stay,
    the doctors on duty learn the results of test T1. A little later they learn the results of
    test T2. Is it possible that, considered separately, positive results on T1 and T2 might
    each increase the chance of A (i.e., P(A|T1) > P(A), and P(A|T2) > P(A)), but that if
    both are known to be positive they decrease the chance of A (i.e., P(A|T1; T2) < P(A))?
    Explain your answer either with a clear example or in the style of a mathematical
    demonstration.

    Any help? Having trouble understanding the question...
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor

    Joined
    Aug 2006
    Posts
    18,709
    Thanks
    1639
    Awards
    1

    Re: question on probability and bayes

    Quote Originally Posted by amma0913 View Post
    Let A be the event that a patient has cancer. In the course of a hospital stay,
    the doctors on duty learn the results of test T1. A little later they learn the results of
    test T2. Is it possible that, considered separately, positive results on T1 and T2 might
    each increase the chance of A (i.e., P(A|T1) > P(A), and P(A|T2) > P(A)), but that if
    both are known to be positive they decrease the chance of A (i.e., P(A|T1; T2) < P(A))?
    Explain your answer either with a clear example or in the style of a mathematical
    demonstration.

    Question: Do we know if the events T_1~\&~T_2 independent or not?
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Junior Member
    Joined
    Jan 2009
    Posts
    57

    Re: question on probability and bayes

    Yes, they're independent.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Bayes Probability - Rain and Umbrellas
    Posted in the Statistics Forum
    Replies: 1
    Last Post: July 11th 2010, 04:06 PM
  2. Probability-Bayes Theorem
    Posted in the Advanced Statistics Forum
    Replies: 1
    Last Post: May 5th 2010, 11:13 PM
  3. Conditional Probability and Bayes' Theorem
    Posted in the Advanced Statistics Forum
    Replies: 1
    Last Post: October 16th 2008, 05:35 AM
  4. Probability and Bayes' formula
    Posted in the Advanced Statistics Forum
    Replies: 5
    Last Post: September 28th 2008, 04:27 AM
  5. probability bayes theorem
    Posted in the Advanced Statistics Forum
    Replies: 1
    Last Post: April 16th 2007, 07:55 PM

Search Tags


/mathhelpforum @mathhelpforum