On July 1, 2017, Sport Company purchased for $3,600,000 snow-making equipment having an estimated useful life of 5 years with an estimated salvage value of $150,000. Depreciation is taken for the portion of the year the asset is used.

Assume the company had used straight-line depreciation during 2017 and 2018. During 2019, the company determined that the equipment would be useful to the company for only one more year beyond 2019. Salvage value is estimated at $200,000

Compute the amount of depreciation expense for the 2019 income statement.

My question is, when calculating the new depreciation for the year with the change in estimate in 2019, do I take into account that only part of the year is depreciated the first year ? Or in other words, from the problem above, do I put 4.5 as the remaining useful life for the new annual depreciation ? (since 2017 was partially depreciated, and 2018 was fully depreciated, so that is 1.5 years worth of depreciation already, and the new estimate added one more year of useful life). What is the remaining useful life after the estimate and why ?