Required a. Calculate each year's depreciation expense for the period under each of the following depreciation methods (round all answers to the nearest dollar): 1. Straight-line. 2. Double-declining balance. 3. Units-of-production. (Assume annual production in platings of 140,000;180,000; 100,000; 110,000; 80,000; and 90,000.) 1. Straight-Line 2. Double-declining balance 3. Units of Production b. Assume that the machine was purchased on September 1. Calculate each year's depreciation expense for the period under each of the following depreciation methods: 1. Straight-line. 2. Double-declining balance