Part 1. 

A machine costing $22,000 with a five-year life and an estimated $2,000 salvage value is installed on January 1. The manager estimates the machine will produce 1,000 units of product during its life. It actually produces the following units: 200 in Year 1, 400 in Year 2, 300 in Year 3, 80 in Year 4, and 30 in Year 5. The total units produced by the end of Year 5 exceed the original estimate—
this difference was not predicted. (The machine must not be depreciated below its estimated salvage value.) Computedepreciation for each year under straight-line, units-of- production, and double-declining-balance.
Part 2.

In early January, a company acquires equipment for $3,800.
The company estimates this equipment has a useful life of three years and a salvage value of $200. On January 1 of the third year, the company changes its estimates to a total four-year useful life and zero salvage value. Using the straight-line method, what is depreciation expense for the third year?