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Maths s1 urgent question on binomials in paper

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    7bii) may2009 st : "calculate the probrability, when sorting a batch of 35 letters, mrs fewer sorts atleast one letter incorrectly. This is a binomial distribution question, but I have no idea how to go about it, since n=35 table isn't in the formula booklet, and I've tried using the formula, (using x=0 and x=1) but the answer made no sense. I couldn't understand the markscheme either. Thanks for any replies!! (P=0.06) for this. Each sorting of a letter may be assumed to be in dependant.
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    Just work out the probabality she sorts none incorrectly and subtract the answer from 1, atleast this is what i'd do, not sure if it's correct :/
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    (Original post by CallumTM)
    Just work out the probabality she sorts none incorrectly and subtract the answer from 1, atleast this is what i'd do, not sure if it's correct :/
    Thats what I did, I substituted x=0 and got 1 as the answer but that cant be right?
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    The distribution of wrongly sorted letters is
    Bin(35,0.06)

    The chance of zero mistakes is
    35C0*(0.06)0*(0.94)35

    Then subtract from 1

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Updated: May 17, 2012
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