5 (Chapter 6) Optional. 2 points Extra Credit for perfect answer, showing work. (Hint: Do this on an Excel spreadsheet.) Operating costs of an automobile in TravelX Inc.'s automotive pool (for its employees) are as follows for a car in year t of its age (e.g., year 1, year 2, etc.): t 1 1000 2 1250 3 1700 4 2200 5 3500 6 5000 Cost of auto replacement are $20,000. TravelX's discount rate is 10%. Salvage value if a car is sold at age t is: 1 12,000 2 10,000 3 8,000 4 5,500 5 3,500 6 2,000 What is the optimal age of replacement for an auto in TravelXs fleet? What is the equivalent annual cost of this auto