Machinery purchased for $63,600 by Skysong Co. in 2016 was originally estimated to have a life of 8 years with a salvage value of $4,240 at the end of that time. Depreciation has been entered for 5 years on this basis. In 2021, it is determined that the total estimated life should be 10 years with a salvage value of $4,770 at the end of that time. Assume straight-line depreciation. Prepare the entry to correct the prior years' depreciation, if necessary. (If no entry is required, select "No entry" for the account titles and enter O for the amounts. Credit account titles are automatically indented when amount is entered. Do not indent manually.) Account Titles and Explanation eTextbook and Media List of Accounts Debit Credit Prepare the entry to record depreciation for 2021. (If no entry is required, select "No entry" for the account titles and enter O for the amounts. Credit account titles are automatically indented when amount is entered. Do not indent manually. Use Machinery related account.) Account Titles and Explanation eTextbook and Media List of Accounts Debit Credit