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Question about probability of union

  1. Jan 9, 2010 #1
    If x1, x2 positive random variables and we have the following two events:

    A={x1 > δ}
    B={x2> k-δ}

    where 0<δ<k

    then is it true that:

    P(A U B) = P( x1+x2 > δ+(k-δ)=k ) ?

    If true can you explain why is that?
    Thank you
     
    Last edited: Jan 9, 2010
  2. jcsd
  3. Jan 9, 2010 #2

    tiny-tim

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    Hi St41n! :wink:

    No, P(A U B) means the probability that either A or B is true.

    So P(A U B) = P(x1 > 1 or x2 > 1). :smile:
     
  4. Jan 9, 2010 #3
    yes i know this is the definition of P(A U B), but does it imply anything about the sums when we have inequalities?

    Also, I made some changes to my original post. Can you take a look again?
     
  5. Jan 9, 2010 #4

    tiny-tim

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    You can't add inequalities like that, it just doesn't work.
    Sorry, still doesn't work.
     
  6. Jan 9, 2010 #5
    Ok I see, thanks
     
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