13. A machine with a cost of $120,000 has an estimated residual value of $15,000 and an estimated life of 5 years or 15,000 hours. It is to be depreciated by the units-of-output method. What is the amount of depreciation for the second full year, during which the machine was used 5,000 hours? a. $5,000 $35,000 $21,000 $45,000 d. 14. A machine with a cost of $75,000 has an estimated residual value of $5,000 and an estimated life of 4 years or 18,000 hours. What is the amount of depreciation for the second full year, using the double-declining-balance method? a. $17,500 b. $37,500 $18,750 d. $16,667