Results 1 to 1 of 1

Math Help - Disease prevalence

  1. #1
    Member
    Joined
    Nov 2008
    Posts
    76

    Disease prevalence

    I'm stumped on this question.

    Conditions:

    Let PPVa = P[D|Ta]
    Let PPVb = P[D|Tb intersection Tb]

    Let SigmaA = P[Ta|D] = P[Ta|D intersection Tb]
    Let KappaA = P[Ta complement|D complement]

    Let SigmaB = P[Tb|D]
    Let KappaB = P[Tb complement|D complement]

    P[D|Ta intersection Tb] > P[D|Ta]

    Attempt at a solution:

    P[D intersection Ta intersection Tb]/P[Ta intersection Tb] > P[D intersection Ta]/P[Ta] (by condtional probability)

    P[D]P[Tb|D]P[Ta|D intersection Tb]/P[Ta intersection Tb] > P[D]P[Ta|D]/P[Ta] (by event composition)

    P[Tb|D]/P[Ta intersection Tb] > 1/P[Ta]

    P[Tb|D] > P[Ta intersection Tb]/P[Ta]

    SigmaB > P[Tb|Ta] (by conditional probability)

    I don't know where to go from there. Some help would be greatly appreciated. The answer is supposed to be: SigmaB > 1 - KappaB.
    Attached Thumbnails Attached Thumbnails Disease prevalence-untitled.jpg  
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Test for a certain disease
    Posted in the Statistics Forum
    Replies: 3
    Last Post: October 20th 2010, 09:04 PM
  2. Spread of a disease
    Posted in the Calculus Forum
    Replies: 1
    Last Post: December 14th 2009, 08:49 PM
  3. decrease of disease
    Posted in the Pre-Calculus Forum
    Replies: 2
    Last Post: September 29th 2009, 03:15 PM
  4. Modeling disease
    Posted in the Calculus Forum
    Replies: 2
    Last Post: May 3rd 2009, 01:48 AM
  5. Disease Probability
    Posted in the Statistics Forum
    Replies: 1
    Last Post: September 25th 2007, 11:16 AM

Search Tags


/mathhelpforum @mathhelpforum