Manipulating the sample variance formula

Hello.

I am trying to prove the identity in red. (My failed attempt is in black)
http://img813.imageshack.us/img813/7396/ideny.png

Quote:

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Originally Posted by incblue

Hello.

I am trying to prove the identity in red. (My failed attempt is in black)
http://img813.imageshack.us/img813/7396/ideny.png

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If you multiply out the numerator of the red LHS,
then use the fact that



the result follows.

Quote:

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Originally Posted by Archie Meade

If you multiply out the numerator of the red LHS,
then use the fact that



the result follows.

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Thanks, it was easy after applying that.