After four years of using a machine acquired at a cost of \(\$ 15,000\), Miller Construction Company determined that the original estimated life of 10 years had been too short and that a total useful life of 12 years was a more reasonable estimate. Explain briefly the method that should be used to revise the depreciation program, assuming that straight-line depreciation has been used and the machine has no residual value. Assume that the revision is made after recording depreciation and closing the accounts at the end of four years of use.