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Homework Help: Statistics and Discrete distributions

  1. May 26, 2014 #1
    1. The problem statement, all variables and given/known data
    The probabilities of blood types O, A, B and AB are 0.46, 0.39, 0.12, 0.03 respectively.
    If a clinic is seeking either type O or B from six random individuals, what is the probability that at least 2 people have the desired blood type?

    2. Relevant equations

    3. The attempt at a solution

    I'm not really sure where to start. From the questions, I dont think it's a binomial distribution or a poisson distribution. All i have so far is...

    Where X=people with the desired blood type

    P(X≥ 2)=1-P(0)-(P(1)

    Any suggestions?
  2. jcsd
  3. May 26, 2014 #2


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    Since the probability of being O is 0.46 and the probability of being B is 0.12, what is the probability of being either O or B?

    What is the probability of not being either O or B, or in other words, what is the probability of being A or AB?
  4. May 26, 2014 #3


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    You are conducting six independent trials, in which success in a trial is defined as "this person has type O or B blood". That gives you a binomial distribution.
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