3. A contractor is considering the following two alternatives: a. Purchase a new microcomputer system for $16,000. The system is expected to last 8 yr with a salvage value of $1,000. 13. Lease a new microcomputer system for $4,000 per year, payable in advance. The system should last 8 yr. If a MARR of 8% is used, which alternative should be selected using a discounted present worth analysis? If the MARR is 16%, which alternate should be selected