In a Multiple Regression Analysis,the Least Squares Prediction Equation Is $\hat { y }$

Multiple Choice

In a multiple regression analysis,the least squares prediction equation is computed as $\hat { y }$
= 84.2 + 6.3x₁ - 9.4x₂.If we hold x₂ constant and increase x₁ by 2 units,what is the estimated change in the mean value of y?

A) -18.8
B) -9.4
C) 12.6
D) 6.3
E) 90.5