In a multiple regression, the following sample regression equation is obtained:
? = 140 + 12.9x1 + 2.7x2.
a. Predict y if x1 equals 20 and x2 equals 30. (Round your answer to 1 decimal place.)
b. Interpret the slope coefficient of x1.
As x1 increases by one unit, y is predicted to decrease by 2.7 units, holding x2 constant.
As x1 increases by one unit, y is predicted to increase by 2.7 units, holding x2 constant.
As x1 increases by one unit, y is predicted to increase by 12.9 units, holding x2 constant.
As x1 increases by one unit, y is predicted to decrease by 12.9 units, holding x2 constant.