Sony Corp. purchased a new machine on Jan 1, 2014. The cost of this machine was $500,000. The company estimated that the machine would have a salvage value of $20,000 at the end of its service life. The estimated service life is 4 years and its estimated total working hours are 25,000 hours. Year-end is December 31. 1. Assuming 5,000 hours used in 2014, compute the depreciation expense for the year of 2014 under Activity method. 2. Compute the depreciation expense for the year of 2014 under Straight-line depreciation method. 3. Compute the depreciation expense for the year of 2014 under Sum-of-the-years-digits method. 4. Compute the depreciation expense for the year of 2014 under Double-declining balance method (i.e., m=2). 5. Compute the depreciation expense for the year of 2017 under Double-declining balance method (i.e., m=2).