Machinery is purchased on January 1 of the current fiscal year for $180,000. It is expected to have a useful life of 4 years, or 20,000 operating hours, and a residual value of $15,000. Compute the depreciation for the last six months of the current fiscal year ending December 31 by each of the following methods: (a) (b) (c) straight-line units-of-production (used for 1,500 hours during the current year) declining-balance ANS: (Round the answer to the nearest dollar.)