Results 1 to 2 of 2

Math Help - independant events, probability

  1. #1
    Super Member
    Joined
    Sep 2008
    Posts
    607

    independant events, probability

    Events A and B are independent.
    Given also that
    P(A) = 3/4 and P(A ∩ B ′ ) = 1/4

    Find
    (a) P(A ∩ B),
    (b) P(B),
    (c) P(A′ ∩ B ′ ).
    can someone please explain in this question If events and A and B are independent of each other, than why is it that the p (A ∩ B ′) = 1/4?
    Is that not the probability that event 'A' happens and 'B' does not , should it not also equal 3/4 ? As my understanding is if both events are independent of each other than the probability of 'A' happening is the same weather or not 'B' has happened.



    Thanks.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor

    Joined
    Aug 2006
    Posts
    18,649
    Thanks
    1597
    Awards
    1
    If events E~\&~F are independent then that tell you P(E \cap F) = P(E)P(F).
    Each of these pairs is independent: E~\&~{F'}, {E'}~\&~F, {E'}~\&~{F'}.

    So you know that \frac{1}{4} = P(A \cap B') = P(A)P(B').
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. independant events
    Posted in the Advanced Statistics Forum
    Replies: 3
    Last Post: August 10th 2011, 07:06 PM
  2. Independant events
    Posted in the Statistics Forum
    Replies: 3
    Last Post: August 13th 2010, 01:36 PM
  3. independant events
    Posted in the Statistics Forum
    Replies: 3
    Last Post: April 22nd 2010, 03:33 AM
  4. Independant/ Dependant Events
    Posted in the Statistics Forum
    Replies: 2
    Last Post: November 8th 2009, 01:04 AM
  5. Independant events.
    Posted in the Statistics Forum
    Replies: 1
    Last Post: October 24th 2009, 04:45 PM

Search Tags


/mathhelpforum @mathhelpforum