XYZ Co. incurred the following transactions concerning its computer:

Jan. 8, 2015 - Purchase the computer with a base price of $3,500 plus special hard disk drive that cost $2,800. Estimated useful life is 5 years and residual value is $300. Straight-line depreciation is to be used.

Jan. 1, 2016 - Changed estimated useful life from 5 years to 4 years.

Jun. 1, 2017 - Paid $150 for regular maintenance on the computer.

Oct. 1, 2017 - Paid $2,575 for a major overhaul of the computer that extended the useful life by 2 years. However, it was now estimated that there woud be no residual value at the end of the computer's useful life.

XYZ Co. uses the calendar year as its fiscal year. A) Prepare the journal entry to record depreciation expense for 2015. B) Prepare the journal entry to record depreciation expense for 2016. C) Prepare the journal entry to record the depreciation expense for 2017. Round all calculations to the nearest whole month.

*** I need help with 2017. I've got 2015 & 2016 figured out. I also know i need to ignore my maintenance expense in that calculation. I'm blocking for 2017, i know i'm going to pro-rate because the expense that extended the useful life was in October but I'm not sure how to go about it. Ex: carrying amount end of 2016 / 3 x 10/12... I'm missing something... Help, thanks!