Wardel Company purchased a mini computer on January 1, 2009, at a cost of $48,000. The computer has been depreciated using the straight-line method over an estimated four-year useful life with an estimated residual value of $4,800. On January 1, 2011, the estimate of useful life was changed to a total of 9 years, and the estimate of residual value was changed to $1,080.
(1) Prepare the appropriate adjusting entry for depreciation in 2011 to reflect the revised estimate.