A large standby electricity generator in a hospital operating room has a first cost of $74,250 and may be used for a maximum of 6 years. Its salvage value, which decreases by 15% per year, is described by the equation S=74,250(10.15)n, where n is the number of years after purchase. The operating cost of the generator will be constant at $7,500 per year, and the interest rate is 12% per year. Determine the economic service life and associated AW values. The economic service life is years and the AW value is $