On January 1, 2013, Zane Manufacturing Company purchased a machine for $40,000. The company expects to use the machine a total of 24,000 hours over the next 6 years. The estimated sales price of the machine at the end of 6 years is $4,000. The company used the machine 8,000 hours in 2013 and 12,000 in 2014. What is depreciation expense for 2013 if the company uses double-declining-balance depreciation