Question about sample variance formula

Hi,

I saw this formula when reading the Wikipedia article on Bessel's correction.

http://upload.wikimedia.org/math/9/5...e82e351e19.png

Can you please explain to me the steps that must be taken to come to the expression on the right?

Thank you very much.

Re: Question about sample variance formula

You can start by expanding the brackets on the left and then splitting the sum into separate sums.

Post your results for those steps if you like.

Re: Question about sample variance formula

which Variance formula on excel is the main one to use?

bar stool