Finding the Line of Best Fit – Linear Regression
ENTER THE DATA –
Go to STAT. Choose EDIT and put the independent variable data into L1 and the dependent variable data in L2. (One
way to clear existing data is to DEL each piece of data. Or clear the whole list with 2nd MEM then ClrAllLists.)
SEE THE DATA –
Before you do anything, press the Y= button and clear/turn off any existing equations.
Then, choose a window for your data. Select WINDOW. Choose Xmin to be smaller than your smallest x value and Xmax
to be larger than your largest x value. Choose Ymin to be smaller than your smallest y value and Ymax to be larger than
your largest y value. (I like to choose negative values for the mins so I can see the axes – up to you.) Ignore the rest of
the choices on the screen.
Finally, turn on your STATPLOT (2nd Y= button). Select Plot1. Highlight On and press ENTER. Make sure you have
highlighted the scatter plot (first option) and have selected L1 for Xlist and L2 for Ylist.
Press GRAPH and look at your data - does it look linear?
GET A BEST-FITTING EQUATION –
Go back to STAT and choose CALC, then LInReg (ax+b) Press ENTER twice (or go down to Calculate and press ENTER).
Write down the equation you get (rounding is OK).
Go to Y= and enter the equation you just wrote down. Press GRAPH to see the equation go over the data points. Press
TABLE (2nd GRAPH) to use your equation to predict values.
Finding the Line of Best Fit – Linear Regression
ENTER THE DATA –
Go to STAT. Choose EDIT and put the independent variable data into L1 and the dependent variable data in L2. (One
way to clear existing data is to DEL each piece of data. Or clear the whole list with 2nd MEM then ClrAllLists.)
SEE THE DATA –
Before you do anything, press the Y= button and clear/turn off any existing equations.
Then, choose a window for your data. Select WINDOW. Choose Xmin to be smaller than your smallest x value and Xmax
to be larger than your largest x value. Choose Ymin to be smaller than your smallest y value and Ymax to be larger than
your largest y value. (I like to choose negative values for the mins so I can see the axes – up to you.) Ignore the rest of
the choices on the screen.
Finally, turn on your STATPLOT (2nd Y= button). Select Plot1. Highlight On and press ENTER. Make sure you have
highlighted the scatter plot (first option) and have selected L1 for Xlist and L2 for Ylist.
Press GRAPH and look at your data - does it look linear?
GET A BEST-FITTING EQUATION –
Go back to STAT and choose CALC, then LInReg (ax+b) Press ENTER twice (or go down to Calculate and press ENTER).
Write down the equation you get (rounding is OK).
Go to Y= and enter the equation you just wrote down. Press GRAPH to see the equation go over the data points. Press
TABLE (2nd GRAPH) to use your equation to predict values.