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Homework Help: Stats question

  1. Sep 30, 2007 #1
    1. The problem statement, all variables and given/known data
    Suppose that A and B are two events of a sample space S such that P(A) = 0.7, P(B) = 0.6 and P(AinterceptB) = 0.4.
    What are the probabilities of the following:
    1. A occurs and B does now
    2. Exactly one of the two events occurs
    3. Neither event occurs.

    I have tried this but the issue I am having is that I'm confused by the wording. We didn't really do anything like this in class, so I have no examples which coincide. Any help?

    Thank you!
     
  2. jcsd
  3. Sep 30, 2007 #2

    rock.freak667

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    P(A/B)= p(AnB)/P(B) which is the probability that B occurs given that A has already occured
    to find the Probabilities...write out the the probability that you have to find...e.g P(A or B occuring) etc...
     
  4. Sep 30, 2007 #3
    Hey

    Sorry, I meant, "A occurs but B does not"... Would that simply be P(A)?
     
  5. Sep 30, 2007 #4

    rock.freak667

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    If P(A) means the probability that A occurs then for A to occur and B not to occur

    then you'd want P(AnB')
     
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