Regression

Excel provides a feature to fit data to a variety of functions. Once the data is graphed and a trendline is added to the graph, the equation of that trendline can be used to calculate the residuals for each data point. The residuals can then also be graphed according to the original independent variable values in order to determine if that function is a good fit for the data. If there is a pattern in the residuals, this indicates that the function is not a good fit for that data set.

• Regression practice spreadsheet: This spreadsheet contains several data sets, graphs with trendlines and calculated residuals.
• AIDS data set: Reported number of AIDS cases by year within the U.S.in a spreadsheet.
• Lab sheet: for use with AIDS data set for learning about regression modeling.
• Data: What function models this data?

Interactivate resources on regression

• Regression Activity
• Discussion on Bivariate Data
• Discussion on Correlation Coefficients
• Discussion on Finding Residuals
• Discussion on Graphing and Interpreting Bivariate Data
• Discussion on Using Residuals to Identify a Line of Good Fit

Tips and Troubleshooting When Graphing a Scatter Plot and Graphing the Residuals using Excel: View as a PDF or as a Word Document.