7. A sanitary sewer may be run either through a deep cut or installed with a lift station, with costs estimated as follows. Lift Station Extra cost of the Cl pipe Extra cost of the lift station Annual operating expenses Expected life Deep Cut $ 50,000 13 $ 500/year 40 years 6%/year S 20,000 $ 2.000/year 20 years Interest rate 6%/year a) Determine best alternative using Present Worth Analysis and LCM method. b) Determine best alternative using Present Worth Analysis and a 10 year study period method. o e 9 d