A4. In the example at the end of the chapter (the study by Kanak et al.), could the researchers have used a continuous variable for number of units? Why do you think they used a four-category variable...

A4. In the example at the end of the chapter (the study by Kanak et al.), could the researchers have used a continuous variable for number of units? Why do you think they used a four-category variable to represent this independent variable? Is there evidence in Table 4 that the linearity assumption would have been violated if a continuous variable had been used?