Exercises Methods 32. Consider a regression study involving a dependent variable y, a quantitative independent variable x, and a categorical independent variable with two levels (level 1 and level 2). a. Write a multiple regression equation relating x, and the categorical variable to y. b. What is the expected value of y corresponding to level 1 of the categorical variable? C. What is the expected value of y corresponding to level 2 of the categorical variable? d. Interpret the parameters in your regression equation.