7. A used tracked dozer costs $135,000. It will be operated for 5 years, when it will be sold for an estimated value of $65,000. It will cost $80,000 to maintain and operate for the first year. This will increase by $5,000 per year over the life of the machine. If the prevailing rate for interest, insurance, taxes, and storage is 14%; what is the equivalent annual cost of owning and operating the machine? (15 Points) 8. A contractor has purchased a small excavator for $280,000 that she plans to use for 10 years. She anticipates that the used excavator can be sold for $25,000 after 10 years of use. Average annual earnings generated by the excavator are estimated to be $125,000, and the average operating and labor costs are estimated to be $75,000. What is the estimated rate of return that the excavator will generate for the contractor? (20 Points)