SOLVED:Consider a regression study involving a dependent variable y, a quantitative independent variable x_{1}, and a categorical variable with two levels (level 1 and level 2) \begin{equation} \begin{array}{l}{\text { a. Write a multiple regression equation relating } x_{1} \text { and the categorical variable to } y \text { . }} \\ {\text { b. What is the expected value of } y \text { corresponding to level } 1 \text { of the categorical variable? }} \\ {\text { c. What is the expected value of } y \text { corresponding to level } 2 \text { of the categorical variable? }} \\ {\text { d. Interpret the parameters in your regression equation. }}\end{array} \end{equation}