Have I done this manipulation correctly?
I started with this
http://i46.tinypic.com/2mmya6b.jpg
and rewrote it as this, factoring out sum(ei)
http://i46.tinypic.com/14476vo.jpg
Is this correct? What I am unsure about is the bottom of the fraction, should it be sum(xj-xbar) or sum(xi-xbar)?
It's a question in which the final answer has (xj-xbar) on the bottom of that fraction (once you use common denominator) I am trying to establish if it is a typo.
Re: Have I done this manipulation correctly?
No, that is not correct. The
terms depend upon i and are also in the sums.
Re: Have I done this manipulation correctly?
Oh, so I cant even do that manipulation... :(
The final answer that I had to derive was:
http://i49.tinypic.com/n6kp5.jpg