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Need help with probabilities

  1. Oct 17, 2004 #1
    Hi again...This is my last question for today.
    I know that i send a lot of threads but...i dont have anyone else to help me.

    Most of the times i dont send any solutions.I try but sometimes i dont understand and so...i dont have something to write.I post frequently
    because if i dont give a 50% of correct answers i will not have the chance to write in the final exams...its a stupid rule.

    My last 2 questions for today are.

    1.We must prove that if P(A/B)=1 then P(B compl. / A compl.)=1
    i wrote a lot of things but ..i didnt prove nothing : ~)

    2.A and B are two events with non zero probabilities.
    I must show (prove) if the following are i)correct,ii)faulse iii)correct under some conventions.
    a)if A and B are foreign then they are independent (i dont know if this is the correct word) butif they are foreign P(A[intersect]B)=[empty-set]
    b)if A and B are independent then they are foreign
    c)P(A)=P(B)=0.6 A,B are foreign
    c)P(A)=P(B)=0.6 A,B are independent
  2. jcsd
  3. Oct 19, 2004 #2
    for 1>
    what is the basic definition of P(A/B) ??
    (There is one in terms of intersections!)
    once u have this, simply work through it....

    for 2>
    what u have done with this so far?

    -- AI
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