Results 1 to 2 of 2

Math Help - Compute the probabilities

  1. #1
    Junior Member
    Joined
    May 2006
    Posts
    30

    Question Compute the probabilities

    Question:

    Suppose (Omega) = {a,b,c}, P({a,b}) = 0.7 , and P({b,c}) = 0.6 Compute the probabilities of {a}, {b}, {c}


    Kind of lost with the question.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Grand Panjandrum
    Joined
    Nov 2005
    From
    someplace
    Posts
    14,972
    Thanks
    4
    Quote Originally Posted by mathlg View Post
    Question:

    Suppose (Omega) = {a,b,c}, P({a,b}) = 0.7 , and P({b,c}) = 0.6 Compute the probabilities of {a}, {b}, {c}


    Kind of lost with the question.
    Let A=P({a}), B=P({b}), C=P({c}), then

    A + B + C = 1

    A + B = 0.7

    B + C = 0.6.

    Which is a set of three simultaneous linear equations in three unknowns,
    which can be solved by the usual methods.

    Eq(2) + Eq(3) - Eq(1) gives:

    (A + B) + (B + C) - (A + B + C) = 0.7 + 0.6 - 1

    or:

    B = 0.3.

    The substituting this in to Eq2 gives A=0.4, and into Eq3 gives C=0.3.

    RonL
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 3
    Last Post: September 22nd 2011, 10:46 AM
  2. Approximate joint probabilities using marginal probabilities
    Posted in the Advanced Statistics Forum
    Replies: 0
    Last Post: June 23rd 2011, 05:04 AM
  3. Compute Probabilities by Conditioning
    Posted in the Advanced Statistics Forum
    Replies: 2
    Last Post: September 24th 2009, 07:54 PM
  4. Compute E[X] and P[Y>2]
    Posted in the Advanced Statistics Forum
    Replies: 2
    Last Post: May 4th 2009, 06:00 PM
  5. Compute
    Posted in the Math Topics Forum
    Replies: 0
    Last Post: April 19th 2008, 03:14 AM

Search Tags


/mathhelpforum @mathhelpforum