a. Premiums on insurance policy for factory buildings b. Tires for lawn mowers c. Filter for spray gun used to paint the lawn mowers d. Paint used to coat the lawn mowers, the cost of which is immaterial to the cost of the final product e. Plastic for outside housing of lawn mowers 1. Salary of factory supervisor g. Hourly wages of operators of robotic machinery used in production h. Engine oil used in mower engines prior to shipment i. Salary of vice president of marketing j. Property taxes on the factory building and equipment k. Cost of advertising in a national magazine I. Gasoline engines installed in the lawn mowers m. Electricity used to run the robotic machinery n. Straight-line depreciation on the robotic machinery used to manufacture the lawn mowers o. Salary of quality control supervisor who inspects each lawn mower before it is shipped p. Attorney fees for drafting a new lease for headquarters offices 4. Payroll taxes on hourly assembly line employees r. Telephone charges for company controller's office S. Steering wheels for lawn mowers t. Factory cafeteria cashier's wages u. Cash paid to outside firm for janitorial services for factory V. Maintenance costs for new robotic factory equipment, based on hours of usage W. Cost of boxes used in packaging lawn mowers, which are a significant portion of the total product cost x. License fees for use of patent for lawn mower blade, based on the number of lawn mowers produced y. Steel used in producing the lawn mowers z. Commissions paid to sales representatives, based on the number of lawn mowers sold