LinReg(ax+b)

4:LinReg(ax+b) – Linear Regression line for y = ax + b using x as the predictor (input or independent) variable and y as the predicted (output or dependent) variable.

Clear the home screen.

Set up the calculator for a statistical plot with X-values in L1 and Y-values in L2.

Press 2ND Y=.

Press ENTER.

While the cursor in over ON, press ENTER. This turns on the stat plot.

Press right arrow, down arrow, and ENTER to highlight the first graph.

Press down arrow to Xlist: and press 2ND 1 to put L1.

Press down arrow to Ylist: and press 2ND 2 to put L2.

Clear the home screen (2ND MODE).

Press 2ND 0 (for CATALOG), D, down arrow until you reach DiasgnosticOn.

Press ENTER twice to get the screen at right.

Now, the calculator is ready to receive the data (X-values in L1 and Y-values in L2).

Then we can find the linear regression equation, r, r², and graph the scatterplot and linear regression line.

Clear the home screen.

Enter the numbers 10, 12, 13, 20, 18, and 17 into L1.

Enter the numbers 23, 21, 25, 30, 32, and 40 into L2.

Press 2ND MODE to save the data.

Press STAT, right arrow to CALC, and down arrow to 4:LinReg(ax+b).

Press ENTER.

To find the linear regression equation, r, r², and graph the scatterplot and linear regression line, we need to instruct the calculator.

Press 2ND 1, comma (,), 2ND 2, comma (,) to use L1 for X-values and L2 for Y-values.

Press VARS and right arrow.

Press ENTER to get this screen.

Press ENTER for the results.

Press ZOOM 9 to get the scatterplot and regression line as shown to the right.