Answer
$ŷ=111.2-0.24x_1+5.39x_2+2.956x_3$
Work Step by Step
In MINITAB, enter the protein values in C1, the fat values in C2, the carbohydrates values in C3 and the calories values in C4.
Select Stats -> Regression -> Regression -> Fit Regression Model
Enter C4 in "Responses" and C1 C2 C3 in "Continuous Predictors" The least-squares regression line will be shown in "Regression Equation", where C4 is $ŷ$ (calories), C1 is $x_1$ (protein), C2 is $x_2$ (fat) and C3 is $x_3$ (carbohydrates).
$ŷ=111.2-0.24x_1+5.39x_2+2.956x_3$
