A retrofitted space heating system is being considered for a small office building. the system can be purchased and installed for $120,000, and it will save an estimated 300,000 kilowatt-hours of electric power each year over a six-year period. a kilowatt-hour of electricity costs $0.10, and the company uses a MARR of 15% per year in its economic evaluations of refurbished systems. the market value of the system will be $8,000 at the end of six years, and additional annual operating and maintenance expenses are negligible. Use the benefit cost method to make a recommendation (10.7)