http://www.john-weber.com/

## HOW TO FIND REGRESSION EQUATIONS WITH TI89 CALCULATOR

 Steps Key Sequence Screens 1. Input Data into Lists Press APPS key Press 6 (for Data/Matrix Editor) Press 3 (for New...) Press right arrow key Press 3 (for List) Press down arrow key to Variable and enter a name Press ENTER (for Save) Press ENTER (To exit) NOTE: To enter values, type number, then ENTER. At any time, to move to a different cell, use arrow keys. If the calculator is set to exact, the values will appear as rational numbers. Enter values of independent variable into c1 Enter values of dependent variable into c2 2. Find the Regression Equation Press F5 key Press right arrow key Choose appropriate regression NOTE: In this case I chose ExpReg (i.e., Exponential Regression) Press down arrow key once, then type c1 into box for x, then ENTER NOTE: You may need to press ALPHA key to turn on/off letters. Press down arrow key once, then type c2 into box for y, then ENTER Press down arrow key once, then right arrow key Using arrow keys, select appropriate function, then ENTER Press ENTER (to save) Note the regression values. In this case, the regression equation is y = (0.7978) (0.846468)x. Press ENTER (to exit) 3. Graph the Regression Equation with the Data Press 2nd, then ESC (to quit editor) Press DIAMOND key, then F1 (for Y=) NOTE: Deselect all but the regression equation that you stored above – use up/down arrow keys to select functions, then press F4. Use up/down arrow keys to move to Plot1 Press ENTER Press right arrow key Press 1 (for Scatter) Press down arrow key twice, then type type c1 into box for x, then ENTER Press down arrow key, then type type c2 into box for y, then ENTER Press ENTER (to save) Press F2, then 6 (for ZoomData) NOTE: Press F3 to trace the function. Use left/right arrow keys to move along the data or function and use up/down arrow keys to move between the function and the data.