301541 per year 6.28 For the cash flows shown, use an annual worth comparison and an interest rate of 10% per year. ( a) AW (a) Determine the alternative that is economi- cally best. (b) Determine the first cost required for each of the two alternatives not selected in (a) so that all alternatives are equally acceptable. Use a A spreadsheet to answer this question. X Y Z First cost, $ 90,000 -400,000 650,000 Annual cost, 40,000 -20,000 -13,000 $ per year Overhaul every - 80,000 10 years, $ Salvage value, $ 7,000 25,000 200,000 Life, years 3 10