The company you work for just bought a high end milling machine for $389,000, which the vendor is going to install for an additional $8,950. Your boss has asked you to look into optimizing the mill ownership strategy for your company. The operating cost of the mill is going to be $26,500 in the first year, which is expected to increase by 6% per year after the first year. The resale value of the mill is expected to be 90% of the machine cost in the first year and then decline by 10% per year from there on out. What is the optimal ownership period (economic life) in years assuming a MARR of 11%? 9 6 7 5 8