Briefly explain how the approach to data analysis differs for these combinations of types of predictor variables In addition, explain what kind of graph(s) can be used to represent the nature of interactions for each of these combinations of types of predictor variables.
a. Interaction between two categorical predictor variables (see also Chapter 13).
b. Interaction between a dummy predictor variable and a quantitative predictor variable
c. Interaction between two quantitative predictor variables.