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Say we have to randomly pick k integral numbers out of n. The numbers are from the range < a; b >. What is the expected value of average absolute deviation from the mean for that random subset of k-numbers as the number of drawings approaches infinity?

Sorry if didn't make myself clear. Could you explain the answer so that it is understandable for a not so bright high school student?

EDIT: This is not homework :) Somobody asked me to program a vizualization of Lotto lottery results and I just got curious about the statistics of that.

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    Can you tell us where you came across this question? I would be surprised if it is homework, since you are in high school.2011-08-31
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    Well, I'm not at high school anymore, my math skills are though :)2011-08-31
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    Oops, sorry. I presumed this is not homework. But the current answer feels this could be homework, and hence it is given hint-style. Now that we know this isn't, perhaps a more descriptive answer is appropriate. (I, for one, think that the question is actually fairly non-trivial and interesting.)2011-08-31
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    +1 on non-trivial. There's a reason why one usually uses variance and standard deviation instead of mean absolute deviation -- it's much easier to work with, despite looking more complicated at first glance.2011-08-31
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    Are the numbers picked with or without replacement? Is the 'mean' the observed mean or the 'true' mean?2011-09-30

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