A forklift was purchased for $25,000 and you are tasked with determining the economic service life (when should the forklift be sold?). The estimated operating costs and salvage values are listed below. Assume an interest rate of 5%. Year Operating Cost ($) Salvage Value ($) 1 -2.500 21,000 2 -3,000 20,000 3 -3,500 19,000 4 -4,000 18,000 5 -4,500 17,000 6 -5,000 16,000 0 Year 4 O Year 6 O Year 5 O Year 3