**How to get the T-83 or T-83 Plus
to do a Linear Regression**.

- Press the
**STAT**button. - Select EDIT.
- Under L
_{1}, enter your x values. - Under L
_{2}, enter your y values. - Press the
**STAT**button again. - Select CALC.
- After the “LinReg(ax+b)” that appears type in L
_{1}, L_{2}. Don’t leave a space, and don’t forget the comma.

What the calculator
is doing is that it’s drawing the best possible straight line through data
points. It’s making sure that the sum of the errors of points above the line
cancels with the sum of the errors of point below the line. It then gives you
the slope(*a*)
and y intercept(*b*) for such a line.
The *r* value gives you an idea of how
close your points are to the line. The closer r is to one, the better the data
points are.