The estimated regression equation for a model involving two independent variables and 10 observations follows. ý = 29.1170 + 0.5504x, + 0.4940x2 (a) Interpret b, in this estimated regression equation. O b, = 0.5504 is an estimate of the change in y corresponding to a 1 unit change in x, when x, is held constant. O b, = 29.1170 is an estimate of the change in y corresponding to a 1 unit change in x, when x, is held constant. O b, = 0.5504 is an estimate of the change in y corresponding to a 1 unit change in x, when x, is held constant. O b, = 0.4940 is an estimate of the change in y corresponding to a 1 unit change in x, when x, is held constant. = 0.4940 is an estimate of the change in y corresponding to a 1 unit change in x, when x, is held constant. O b, Interpret b, in this estimated regression equation. O b, = 0.4940 is an estimate of the change in y corresponding to a 1 unit change in x, when x, is held constant. O b, = 0.4940 is an estimate of the change in y corresponding to a 1 unit change in x, when x, is held constant. O b, = 29.1170 is an estimate of the change in y corresponding to a 1 unit change in x, when x, is held constant. O b, = 0.5504 is an estimate of the change in y corresponding to a 1 unit change in x, when x, is held constant. O b, = 0.5504 is an estimate of the change in y corresponding to a 1 unit change in x, when is held constant. (b) Predict y when x, = 160 and x,2 = 320.