6.. NPV12=? (12yr lifetime for project) 11.7 An air compressor is needed in a manufacturing plant. Two compressor manufacturers have submitted bids with the following schedules: Compressor A Compressor B Initial cost, $ Useful life in years Annual operating cost, $ Salvage at the end of useful life, $ 4000 10 800 1000 8000 15 500 2000 See below, You can use any interest rate. Compare NPV at end of 12th Year