Final answer:
The correct depreciation in the third year after adjusting for the extended useful life is $1,716. This is calculated by deducting the accumulated depreciation from the original cost to get the book value and then spreading the remaining amount over the new remaining useful life.
Step-by-step explanation:
The student's question involves calculating the depreciation of an asset after an adjustment to its useful life. The asset originally cost $15,500 with a residual value of $1,200 and had an expected useful life of 5 years. The straight-line method of depreciation was used for two years. In the third year, the useful life of the asset was determined to be 2 years longer than initially expected.
To calculate the depreciation in the third year, first, we need to calculate the total depreciation for the first two years. The annual depreciation for the first two years is ($15,500 - $1,200) / 5 years = $2,860 per year. After two years, the accumulated depreciation is $2,860 * 2 = $5,720. The book value at the beginning of the third year is $15,500 - $5,720 = $9,780.
With the extension of the useful life by 2 more years, the new total useful life becomes 7 years. Since depreciation has already been charged for 2 years, the remaining useful life is 5 years. Therefore, the new annual depreciation from the third year onward is ($9,780 - $1,200) / 5 years = $1,716.