Six years ago, an 75-kW diesel electric set cost $180,000. The cost index for this class of equipment six years ago was 185 and is now 199. The cost-capacity factor is 0.5. a. The plant engineering staff is considering a 120-kW unit of the same general design to power a srpall isolated plant. Assume we want to add a precompressor, which (when isolated and estimated separately) currently costs $17,500. Determine the total cost of the 120-kW unit. b. Estimate the cost of a 50-kW unit of the same general design. Include the cost of the $17,500 precompressor. a. The total cost of the 120-kW unit is $ (Round to the nearest dollar.) b. The cost of a 50-kW unit of the same general design is $ (Round to the nearest dollar.)