CST-33806 restaurant produces and sells hamburgers. Each burger sells for $ 12. During December, the restaurant sold 10,000 burgers (the average amount sold each month). The restaurant employs cooks, servers, and one supervisor (the owner, Carol Johnson). All cooks and servers are part-time employees. The restaurant maintains a pool of part-time employees so that the number of employees scheduled can be adjusted to the changes in demand. A janitor is hired to clean the building on a weekly basis. The building is leased from a local real estate company. The building has no seating capabilities. All orders are filled on a drive-through basis. The supervisor spends 60% of her time supervising food production, and the balance of her time supervising counter staff and on various other sales and administrative activities. The following costs were incurred during December: Hamburger Meat $ 5,000 Lettuce $ 1,600 Tomatoes $ 1,500 Buns $ 1,200 Cook's wages $ 14,000 Server's wages $ 10,000 Supervisor's salary $ 15,000 Utilities $ 2,100 Depreciation - cooking equipment $ 600 Depreciation - cash register $ 500 Advertising $ 700 Rent $ 1,000 Janitorial expenses $ 400 Utility costs consist of a $ 1,100 fixed cost with the balance depending