PE 9-12 Changes in Depreciation Estimates Consider the following data for Kathleen's Tropical Resorts, Inc. Cost of machine.. Estimated useful life (years).. .. Salvage value Estimated useful life (units). Units produced during the first year $1,000000 8 years $40,000 ,600,000 180,000 Assume Kathleen's computed depreciation expense of $120,000 per year. After three years determined that the machine would last eight more years (for a total of 11 years expense for the fourth year. Kathleen's