Consider a regression study involving a dependent variable y, a quantitative independent variable x 1, and a categorical independent variable with two levels (level 1 and level 2). a. Consider the following regression equation relating x 1 and the categorical variable to y. E(y) = Bo + B 1 x 1 + B 2x2 Enter the values of dummy variable x 2 that are used to indicate the two levels of the qualitative variable. X2 Level 1 Level 2