In a regression analysis involving 30 observations, the following estimated regression equation was obtained. y = 17.8 + 3.3x1 - 2.4X2 + 7.7X3 + 2.8X4 (a) Interpret bj in this estimated regression equation. O b, = 2.8 is an estimate of the change in y corresponding to a 1 unit change in x4 when x1, X2, and x3 are held constant. O b, = 7.7 is an estimate of the change in y corresponding to a 1 unit change in x3 when x1, X2, and x4 are held constant. O b, = 3.3 is an estimate of the change in y corresponding to a 1 unit change in x, when x2, X3, and x4 are held constant. O b, = 3.3 is an estimate of the change in y corresponding to a 1 unit change in X2 when x1, X3, and x4 are held constant. O b, = -2.4 is an estimate of the change in y corresponding to a 1 unit change in x, when x2, X3, and x are held constant. Interpret b, in this estimated regression equation. O b, = -2.4 is an estimate of the change in y corresponding to a 1 unit change in x2 when x1, X3, and x are held constant. O b, = 2.8 is an estimate of the change in y corresponding to a 1 unit change in X4 when x1, X2, and x3 are held constant. O b2 = -2.4 is an estimate of the change in y corresponding to a 1 unit change in x1 when x2, X3, and x4 are held constant. O b2 = 7.7 is an estimate of the change in y corresponding to a 1 unit change in x3 when x1, X2, and x4 are held constant. O b2 = 3.3 is an estimate of the change in y corresponding to a 1 unit change in x, when x2, X3, and x4 are held constant. Interpret b3 in this estimated regression equation. O b3 = 7.7 is an estimate of the change in y corresponding to a 1 unit change in x3 when x1, X2, and x4 are held constant. O b3 = -2.4 is an estimate of the change in y corresponding to a 1 unit change in x, when X2, X3, and x are held constant. O b3 = -2.8 is an estimate of the change in y corresponding to a 1 unit change in x4 when x1, X2, and x3 are held constant. O b3 = 3.3 is an estimate of the change in y corresponding to a 1 unit change in x3 when x1, X2, and x4 are held constant. O b3 = 7.7 is an estimate of the change in y corresponding to a 1 unit change in x2 when x1, X3, and x4 are held constant. Interpret by in this estimated regression equation. O ba = 2.8 is an estimate of the change in y corresponding to a 1 unit change in X3 when x1, X2, and x4 are held constant. O b4 = 7.7 is an estimate of the change in y corresponding to a 1 unit change in X2 when X1, X3, and x3 are held constant. O ba = 2.8 is an estimate of the change in y corresponding to a 1 unit change in X4 when x1, X2, and x3 are held constant. O ba = 3.3 is an estimate of the change in y corresponding to a 1 unit change in x4 when x1, X2, and x3 are held constant. O ba = -2.4 is an estimate of the change in y corresponding to a 1 unit change in x2 when x1, X3, and x4 are held constant. (b) Predict y when x, = 10, X2 = 5, X3 = 1, and X = 2