In a regression analysis involving 30 observations, the following estimated regression equation was obtained.
y = 17.6 + 3.8x1 – 2.3x2 + 7.6x3 + 2.7x4
a. Interpret b1, b2, b3, and b4 in this estimated regression equation.
b. Predict y when x1 = 10, x2 = 5, x3 = 1, and x4 = 2.