On October 1,2021 , the Allegheny Corporation purchased equipment for $115,000. The estimated service life of the equipment is 10 years and the estimated residual value is $5,000. The equipment is expected to produce 220,000 units during its life. Required: Calculate depreciation for 2021 and 2022 using each of the following methods. Partial-year depreciation is calculated based on the number of months the asset is in service. 2. Double-declining-balance