Machinery purchased for $73,200 by Blue Co. in 2016 was originally estimated to have a life of 8 years with a salvage value of $4,880 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 $5,490 at the end of that time. Assume straight-line depreciation. (a) 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 Debit Credit