S 10-7 Computing depreciation under different methods P1 Equipment costing $13,000 with a 10-year useful life and an estimated $3,000 salvage value is acquired and started operating on Jan 1. The equipment is estimated to produce 2,000 units of product during its life. It produced 160 units in the first year. Compute depreciation for the first year under straight-line, units-of-production, and double-declining-balance