# Linear regression and varience.

1. Nov 2, 2005

### matthyaouw

Im having some trouble with this, and I was hoping someone could help me.
I have a data set from which I've determined the $$\widehat{a}$$ and $$\widehat{b}$$ values and determined where the line of best fit should go using linear regression. The next thing I have to do is work out the varience using this equation:

$$\underline{\sum(y-\widehat{y})^2} \\n-2$$
(edit) Sorry, first time using latex, and I can't access the tutorials for some reason.
I've typed :
"\underline{\sum(y-\widehat{y})^2}
\\n-2"
But I'm not getting a new line after ^2}. How do I do this? (/edit)

I'm a bit unsure what to do here. Does that mean that I have to sum up all of my y values, and take away the expected y values that are predicted on my line of best fit which correspond to the actual values I've entered?

Last edited: Nov 2, 2005
2. Nov 2, 2005

### matthyaouw

Never mind, got it (I think). If someone could still tell me what I'm doing wrong with the Latex I'd appreciate it though.