A manufacturing company makes 4,200 parts per year. These parts are used in the assembly of one of the company's products. The unit product cost of these parts is: The part can be purchased from an outside supplier at $40.20 per unit. If the part is purchased from the outside supplier, two-thirds of the fixed manufacturing costs can be estimated. The annual impact on the company's net operating income as a result of buying the part from the outside supplier would be: $18,480 decrease $7,560 decrease $18,480 decrease $7,560 decrease