During September, 40,000 units of product were produced. The standard quantity of material allowed per unit was four kilograms at a standard cost of...

used to manufacture the parts.

$30,000 of depreciation on the equipment used to manufacture the parts.

The supervisor's salary of $25,000, which would be avoided if the part is purchased from an outside supplier.

$15,000 in rent from leasing the production space to another company if the part is purchased from an outside supplier.