Cowboy Grading has just purchased a new skid steer tractor. Now that they have made this purchase, they have asked you to calculate the Optimum Replacement Interval for the tractor. Initial cost: Annual maintenance: Risk allowance: $25,000 $2,000 in first year increasing by $500 per year $5,000 for years 1,2,3 and then increasing by $1,500 per year. (This is a value assigned by the company that estimates the cost associated each year if the tractor has a major breakdown and is taken out of service during the repair period.) $20,000 at year 1, decreasing by 25% each year thereafter. 7 years 15% Salvage value: Assumed useful life: MARR: a. (10 points) Develop the cash flow diagram (or Excel sheet) for 7 years of ownership. b. (20 points) Calculate the AEUC of ownership for 1 year, 2 years.... 7 years. (5 points) At which year should they plan on replacement? C