You obtain the multiple regression equation y̅ = 5 + 3x1 - 4x2 from a set of sample data.
(a) Interpret the slope coefficients for x1 and x2.
(b) Determine the regression equation with x1 = 10. Graph the regression equation with x1 = 10.
(c) Determine the regression equation with x1 = 15. Graph the regression equation with x1 = 15.
(d) Determine the regression equation with x1 = 20. Graph the regression equation with x1 = 20.
(e) What is the effect of changing the value x1 on the graph of the regression equation?