Equipment with a cost of $640,000 has an estimated salvage value of $40,000 and an estimated life of 4 years or 15,000 hours. It is to be depreciated using the units-of-activity method. What is the amount of depreciation for the first full year, during which the equipment was used for 3,300 hours? O $160,000. $150,000. O $180,800. $132,000.