Davis machine works purchased a stamping machine $135,000 on March 1, 2007. The machine is expected to have a useful life of 5 years, salvage value of $12,000, production of 250,000 units, and number of working hours of 30,000. During 2007, Davis used the stamping machine for 2450 hours to produce 23,450 units. From the information given compute the book depreciation expenses for the life of the machine under each of the following methods: (a) straight-line (b) double-declining-balance (without conversion to straight-line depreciation) (c) units of production