Push the key and select "6: Data/Matrix Editor." 

Select:
Since this is your first time in the data/matrix editor, select "3: New." 

This is the New Data Dialog. Leave the type as "Data" and folder as "main". Type the name of your variable in the Variable field  "temp" is a good name for this exercise. You do not need to press [alpha] to type in this field. 

Now you can enter the data values into your variable. It seems easiest type the xvalues into the "c1" column first, then go back and type the yvalues into the "c2" column. (The data shown here is from Stewart, p. 27, Example 2. Note that I have used "0" for "1980," "2" for "1982" to simplify the data somewhat.) 

To fit an equation to your data, press (Calculate). In the Calculate Dialog that opens, set:
then press . 

Here are the results of the linear regression calculation on the data from this example. Correlation ("corr") and "R^{2}" are measures of how closely the data fit the given line. For our purposes, a correlation close to 1 or 1 means "good fit." (The yintercept shown here differs from the one in the text (which is 2707.25) since my xvalues are adjusted from the ones in the text.) 

You can press (Y=) to check that, sure enough, the regression equation has been saved to y1. You can go ahead and graph this line, but it won't show your data points. To get back to your data, press . 

To set up a data plot:


Select (Define). In the Define Plot Dialog, set:
and press . 

Press (Y=) to go to the Y= Editor. Then press (Zoom) and select "9:ZoomData" to graph the data points and the regression line. 

Compare this graph to Fig. 6 on p. 28 of the Stewart text. 
