4. Determine the economic service life and corresponding annual worth value for a machine that has the following cash flow estimates. Use an interest rate of 14% per year and hand solution. Salvage Operating Year Value, s Cost, $ per Year 100,000 75,000 -28,000 60,000 -31,000 50,000 -34,000 40,000 -34,000 25,000 -34,000 15,000 45,000 -49,000