Calculate the amount of depreciation to report during the year ended December 31 for equipment that was purchased at a cost of $25,000 on October 1. The equipment has an estimated residual value of $5,000 and an estimated useful life of five years or 20,000 hours. Assume the equipment was used for 1,000 hours from October 1 to December 31 and the company uses (a) straight-line, (b) double-declining-balance, or (c) units-of-production depreciation.