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Homework Help: Stats proof - unbiasedness of b1

  1. Feb 15, 2012 #1
    We are to prove sum(n)(I=1)(k(I))*(x(I)) = 1

    Where (k(I))= (x(I)-x(bar))/(sum(n)(j=1)(x(j)-x(bar))^2



    Attempt at solution:

    I rearranged it to equal:

    (1/(sum(n)(j=1)(x(j)-x(bar))^2))*(sum(n)(I=1)(x(I)-x(bar))*x(I))

    I don't really know how to proceed. Sorry for the formatting issues, I am on mobile currently.
     
  2. jcsd
  3. Feb 20, 2012 #2
    everything can be written in terms of \sum_i x_i and \sum_i x_i^2, the rest is straightforward
     
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