A commercial oven with a book value of $24,990 has an estimated remaining 5 year life. A proposal is offered to sell the oven for $7,810 and replace it with a new oven costing $44,620. The new machine has a 5-year life with no residual value. The new machine would reduce annual maintenance costs by $8,580. Annual maintenance cost reduction? Number of years applicable ? Total differential decrease in cost? Proceeds from sale of equipment? Cost of new equipment? Net differential decrease in cost from replacing equipment?