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Discrete Distributions

  1. Nov 19, 2015 #1
    One hundred pennies are being distributed independently and at random into 30 boxes, labeled 1, 2, ..., 30. What is the probability that there are exactly 3 pennies in box number 1?

    I tried using a Poisson distribution f(x) = (e^-λ)*(λ^x)/x! , with λ = 100/30 = 10/3 and x = 3. I got 0.22021 (5 s.f.), but the answer key is 0.22345. Am I using the wrong distribution? Thanks!
     
  2. jcsd
  3. Nov 19, 2015 #2

    RUber

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    For any one penny, what is the probability that it will end up in box # 1?
    Use a binomial distribution...N = number of pennies. k = 3. p = probability of landing in box #1.
     
  4. Nov 19, 2015 #3
    Ok I got it! Thanks! :)
     
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