Wardell Company purchased a mainframe on January 1, 2019, at a cost of $52,000. The computer was depreciated using the straight-line method over an estimated five-year life with an estimated residual value of $7,000. On January 1, 2021, the estimate of useful life was changed to a total of 10 years, and the estimate of residual value was changed to $1600. Required: 1. Prepare the year-end journal entry for depreciation in 2021. No depreciation was recorded during the year.