Least Squares Regression Analysis

The controller for TG Enterprises is trying to determine whether direct labor hours or machine hours is driving the company's overhead cost. He collected the following data on the number of direct labor hours, the number of machine hours, and the associated factory overhead cost for the year $2018$:

$\backslash$table$[[$Month$,\backslash$table$[[$Machine$],[$Hours$]],\backslash$table$[[$Oirect Labor$],[$Hours$]],\backslash$table$[[$Overhead$],[$Cost$]]],[$January$,198,1,810,$$$17,610$