Tamarisk Co. purchased equipment for $583,800which was estimated to have a useful life of 10 years with a salvage value of $11,800at the end of that time. Depreciation has been entered for 7 years on a straight-line basis. In 2018, it is determined that the total estimated life should be 15 years with a salvage value of $6,000at the end of that time.

(a)Prepare the entry (if any) to correct the prior years' depreciation.

(b)Prepare the entry to record depreciation for 2018.