- Know what an interaction term is and use a scatterplot to understand the interaction effects
- Write appropriate multiple linear regression model equations for categorical predictors and interaction terms
Step 2: Select “Weight” as the X-Variable, “Pulse1” as the Y-Variable, and “Exercise” as the Grouping Variable
Step 3: Click the Select Linear Regression Equation(s) box to obtained the 3 separate equations for each level of exercise.
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In general, what does it mean for two explanatory variables “to interact”?
Two explanatory variables interact if the effect on the response variable of one explanatory variable depends on the value of the other variable.
This means that we can no longer interpret the slope as the change in the value of the response variable for each unit increase in the explanatory variable, while the other explanatory variables are held constant.