Answer
$ŷ=109.89+0.000029x_2$
Work Step by Step
In MINITAB, enter the MRI Count values in C2 and the IQ values in C3.
Select Stats -> Regression -> Regression -> Fit Regression Model
Enter C3 in "Responses" and C2 in "Continuous Predictors"
The least-squares regression line will be shown in "Regression Equation", where C3 is $ŷ$ (IQ) and C2 is $x_2$ (MRI Count).
$ŷ=109.89+0.000029x_2$
