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Homework Help: Two coin are tossed 4 times ,find?

  1. May 8, 2010 #1
    1)the probability of 2 heads in 4 times ?
    2)the probability of less than one head once?
    3)the probability of more than 2 tails in 3 times ?
    4)the expected number of two tails ?
    5)the variance of the number of 2 heads
  2. jcsd
  3. May 8, 2010 #2


    Staff: Mentor

    What have you tried?
  4. May 8, 2010 #3


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    Staff Emeritus
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    Last edited: May 8, 2010
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