Wardell Company purchased a mini computer on January 1, 2011, at a cost of $34,900. The computer has been depreciated using the straight-line method over an estimated five-year useful life with an estimated residual value of $3,400. On January 1, 2013, the estimate od useful life was changed to a total of 10 years, and the estimate of residual value was changed to $940.

Prepare the appropriate adjusting entry for depreciation in 2013 to reflect the revised estimate.