Include graphs of the average coat models for both energy-efficient and conventional models.

Energy costs. Most appliance manufacturers produce con- ventional and energy-efficient models. The energy-efficient models are more expensive to make but cheaper to operate. The costs of purchasing and operating a 23-cubic-foot refrig- erator of each type are given in Table 8. These costs do not include maintenance charges or changes in electricity prices. Table 8 23-ft Refrigerators Energy-Efficient Model Initial cost $950 Total volume 23 ft Annual cost $56 of electricity Conventional Model $900 23 ft? $66 (A) Express the total cost Ce(x) and the average cost [(x) = C(x)/x of purchasing and operating an energy-efficient model for x years. (B) Express the total cost C (x) and the average cost C.(x) = C.(x)/x of purchasing and operating a conventional model for x years. (C) Are the total costs for an energy-efficient model and for a conventional model ever the same? If so, when? (D) Are the average costs for an energy-efficient model and for a conventional model ever the same? If so, when? (E) Find the limit of each average cost function as x and discuss the implications of the results