| 1. Enter lists | |
  xyvars  |
Clear a data matrix for use |
   |
Use Data/Matrix Editor This is a New variable |
 xyvars |
Type in a variable name; ‘xyvars’ |
| |
|
| Enter x values in c1 and y values in c2;
pressing after
each one |
|
| 2. Graph the data | |
 |
Plot setup |
   |
Define Scatter Box |
| c1
|
x’s are in column 1 |
| c2 |
y’s are in column 2 |
| |
Save the plot definition; return to plot setup screen |
 W |
Go to the Y = screen; check Plot 1; uncheck the rest |
 |
ZoomData; the data is plotted |
| 3. Do the linear regression; the equation will be of the form y(x) = ax + b | |
  |
Quit |
| |
Use Data/Matrix Editor and current data |
  |
Do LinReg |
| c1 |
Use x’s from column 1 |
| c2 |
Use y’s from column 2 |
| |
Store RegEQ to y1(x) |
|
Values of a, b, corr, and r2 appear on screen; a = slope; b = y intercept; corr = r |
| 4. The linear regression equation is in y1; graph it | |
| W |
Go to the Y = screen |
| |
ZoomData; regression line is graphed with data points |
| 5. Use the regression line to make predictions | |
| Q |
Go to the Home screen |
| y1(20) |
Evaluate the regression equation y1 at 20 (or the value of your choice) |
| 6. When regression is completed, turn scatter plots off | |
| W |
Go to the Y = screen and highlight Plot 1: |
|
Uncheck Plot 1: |