Premium Doors Inc. purchased equipment on January 1, 2013, for $250,000. At that time it was estimated that the equipment would have a 5-year life and no salvage value. On December 31, 2014, the firm's accountant found that the entry for depreciation expense had been omitted in 2013. In addition, management has informed the accountant that the company plans to switch to the sum-of-the-years'-digits method for depreciating equipment, starting with the year 2014. At present, the company uses the straight-line method of depreciation.