Solution 12648: Calculating Linear Regressions on the TI-81.
How do I calculate a Linear Regression using the TI-81?
The example below will demonstrate how to perform a linear regression using the TI-81:
Data for this example:
Enter the data into the TI-81:
1) Enter STAT edit mode by pressing [2nd] [STAT].
2) Scroll to DATA.
3) Press .
4) Enter the data as x-y coordinates 1 [ENTER] 7 [ENTER] 4 [ENTER] 9 [ENTER] 8 [ENTER] etc.
5) Press [2nd][QUIT] to leave the editor.
Calculate the Linear Regression (ax+b):
1) Enter the STAT mode again by pressing [2nd] [STAT].
2) Press  to select LinReg.
3) Press [ENTER] to perform the regression calculation.
The graphing calculator will display the form of the equation (y=a+bx) and then list the values for a and b (5.0256 and 1.2564 respectively) and the correlation coefficient (r) .9885.
For more information regarding your Texas Instruments graphing calculator, please refer to the guidebooks section.