In a regression analysis involving 30 observations, the following estimated regression equation was obtained. ŷ = 18.7 + 3.7x₂ - 2.3x₂ + 7.6x3 + 2.9x4 (a) Interpret b, in this estimated regression equation. O b₁ = 7.6 is an estimate of the change in y corresponding to a 1 unit change in x3 when X₁, X₂, and x4 are held constant. = 2.9 is an estimate of the change in y corresponding to a 1 unit change in x4 when X₁, X₂, and x3 are held constant. Ob₁ = Ob₁ = 3.7 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 b₁ = -2.3 is an estimate of the change in y corresponding to a 1 unit change in x₁ when X2, X3, and x4 are held constant. Ob₁ = = 3.7 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 b₂ in this estimated regression equation. O b₂ = -2.3 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 b₂ = 2.9 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 = -2.3 is an estimate of the change in y corresponding to a 1 unit change in x, when X₂ X3, and x4 are held constant. Ob₂= = 7.6 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 = 3.7 is an estimate of the change in y corresponding to a 1 unit change in x₁ when X₂, X3, and x4 are held constant. Interpret b in this estimated regression equation. O b3 = -2.9 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 = 7.6 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 b3 = 3.7 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 = 7.6 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 = -2.3 is an estimate of the change in y corresponding to a 1 unit change in x₁ when X₂, X3, and X4 are held constant. Interpret b in this estimated regression equation. O b4 = -2.3 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 b4 = 7.6 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 b4 = 2.9 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 = 3.7 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 b4 = 2.9 is an estimate of the change in y corresponding to a 1 unit change in x4 when X₁, X₂, and x3 are held constant. (b) Predict y when x₁ = 10, x₂ = 5, x3 = 1, and x4 = 2.