Answer
$ŷ=18.82+0.786x_1+0.0128x_2$
Work Step by Step
In MINITAB, enter the Height values in C1, the Weight values in C2 and the Head Circumference values in C3.
Select Stats -> Regression -> Regression -> Fit Regression Model
Enter C3 in "Responses" and C1 C2 in "Continuous Predictors"
The least-squares regression line will be shown in "Regression Equation", where C3 is $ŷ$ (Head Circumference), C1 is $x_1$ (Height) and C2 is $x_2$ (Weight).
$ŷ=18.82+0.786x_1+0.0128x_2$
