Equipment acquired on January 8 at a cost of $168,000 has an estimated useful life of 18 years, has an estimated residual value of $15,000, and is depreciated by the straight-line method. a. What was the book value of the equipment at December 31 the end of the fourth year? $ b. Assume that the equipment was sold on April 1 of the fifth year for $125,000. 1. Journalize the entry to record depreciation for the three months until the sale date. 2. Journalize the entry to record the sale of the equipment. If an amount box does not require an entry, leave it blank.