Equipment with a cost of $31,000 has an estimated residual value of $3,000 and a estimated life of 4 years or 10,000 hours. It is to be depreciated by the straight-line method. What is the amount of depreciation for the first full year, during which the equipment was used 2,300 hours? $4,000 O $17,000 O $7,000 O $3,000