Recall from Lesson 5B that you can use the diagnostic feature on the graphing calculator to determine if a regression model fits a set of data accurately. Review this feature in Highlights.
The coefficient of determination, R^{2}, measures how well a regression model represents a set of data. It is expressed as a value between zero and one. If R^{2} = 1, the regression curve passes through every point on the scatter plot. This indicates the regression curve models the data exactly. A value of zero indicates the regression curve is not an accurate model for the data. Step 1: Open the CATALOG; press 2^{nd}, 0 (zero), down arrow to scroll to DiagnosticOn. Step 2: Turn on the diagnostic feature; press ENTER, ENTER. |
In Example 3, you will see how the coefficient of determination is used to help determine if a model represents a given set of data accurately.