Linear regression and varience.

AI Thread Summary
The discussion focuses on calculating variance after determining the line of best fit using linear regression. The user is attempting to use a LaTeX equation for variance but is struggling with formatting issues, specifically with line breaks. They seek clarification on whether to sum the differences between actual and predicted y values to compute variance. The user expresses some uncertainty but believes they may have resolved their initial confusion. Assistance with LaTeX formatting remains a key request.
matthyaouw
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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}<br /> \\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:
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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.
 

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