A contractor has been awarded the contract for the construction of a small shopping center. The contractor has decided to use crawler tractors with dozer blades to remove the vegetation and topsoil from the project site, but is unsure which size tractor to use. The productivity of a medium-sized tractor is estimated to be 100 square yards per day, and the productivity for a heavy tractor is estimated to be 190 square yards per day. The average hourly ownership and operating cost (including labor cost) for the medium tractor is $85, and for the heavy tractor is $126.

a) Which tractor should the contractor select to minimize the direct equipment cost for clearing and grubbing the project site?

b) Using the tractor selected above, what is the estimated equipment cost for clearing and grubbing the 200-foot-by-270-foot site?