Depreciation Methods On January 2, 2015, Alvarez Company purchased an electroplating machine to help manufacture a part for one of its key products. The machine cost $218,700 and was estimated to have a useful life of six years or 781.200 platings, after which it could be sold for $23,400. Required a. Calculate each year's depreciation expense for the period 2015-2020 under each of the following depreciation methods: 1. Straight-line. 2. Double-declining balance. 3. Units-of-production. (Assume annual production in platings of 140,000; 180,000; 150,000; 125,000; 105,000; and 81,200.) Assume that the machine was purchased on September 1, 2015. Calculate each year's deprecia- tion expense for the period 2015-2021 under each of the following depreciation methods: 1. Straight-line 2. Double-declining balance. b