On January 1, 2015, Missoula Corporation bought machinery for $800,000. They used double declining balance depreciation for this asset, with an estimated life of eight years, and an estimated $200,000 residual value. At the beginning of 2018, Missoula decided to change to the straight-line method of depreciation for this equipment, and treated the change as a change in estimate. For calendar 2018, the depreciation expense for this machinery is

1. $ 75,050. 
2. $ 92,500. 
3. $ 27,500. 
4. $100,000.