Once we have obtained the scatterplot of the data values, we are ready to find the regression line.

From the scatterpolt, it appears that the correlation coefficient will be positive since the X-values and the corresponding Y-values are increasing.

To obtain the regression line press STAT, then press the RIGHT ARROW to select CALC, then select 4, then ENTER. The screens on your calculator should show

This gives the regression line y = 2.081x - 0.093 (rounded to three decimal places).    In order to get the correlation coefficient r to appear press,  2^nd, then 0 [CATALOG]. Using the arrow keys, arrow down to DiagnosticOn. Then press ENTER to select and then ENTER again to turn on the correlation coefficient.

Now again press STAT, ARROW RIGHT to CALC, then press 4, and then ENTER.   The screen will appear as shown  below.  The regression line is displayed, along with r² and r.

Thus, y = 2.081x - 0.093 and   the correlation coefficient is r 0.998. This is a good fit to the data as the value is very close to 1. 

In order to graph this line, press Y= and enter 2.081X - 0.093 for Y₁ . Then press GRAPH.

Note: Click here, if you wish to see how the regression equation can be automatically copied to Y_1.

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