A small strip-mining coal company is trying to decide whether it should purchase or lease a new clamshell. If purchased, the "shell will cost $135,000 and is expected to have a $60,000 salvage value after 6 years. Alternatively, the company can lease a clamshell for only $20,000 per year, but the lease payment will have to be made at the beginning of each year If the clamshell is purchased, it will be leased to other strip-mining companies whenever possible, an activity that is expected to yield revenues of $14,000 per year if the company's MARR is 18% per year, should the clamshell be purchased or leased on the basis of a future worth analysis? Assume the annual M&O cost is the same for both options. The future worth when purchased is $ The future worth when leased is The clamshell should be (Click to select)