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Homework Help: Statistics, Probability ! Help!

  1. Jul 6, 2011 #1
    1. The problem statement, all variables and given/known data

    The probability that Joe owns a microwave oven is 75%; the probability that he owns a CD player is 45%; and the probability that he owns both is 40%. Find the probability that he owns either one but not both.

    2. Relevant equations

    (work posted below)

    3. The attempt at a solution

    P(only microwave)= .75-.4 = .35
    P(only CD Player) = .45 - .4 = .05
    P(only micr. or CD Pl) = .35 + .05 = .4

    Answer = .4
     
  2. jcsd
  3. Jul 6, 2011 #2
    You got it! Try visualizing it with a Venn diagram: 2 overlapping circles representing probabilities that he owns either or both, surrounded by a large circle that represents probability that he owns either, both, or neither. (Hint: probability he owns neither is 0.2)
     
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