Another question for you all-

Let x1, x2,...xn be a random sample. Show that

or S^2 = 1/2n(n-1) summation(summation( (Xi - Xj)^2 )

It's a little blurry ( I know ), but how would I go about showing that the sample variance is equal to that?

My best guess is to pull the 2n on the bottom in and turning all the xj's to x bar.

Thanks for your help!