4. On July 1, Hartford C tion purchases a bulldozer for $228,000. The equipment has a nine-year life with a residual value of $16,000. Hartford uses the units-of-activity method of depreciation, and the bulldozer is expected to yicld 26,500 opcrating hours. (a) Calculate the depreciation expense per hour of operation. (b) The bulldozer is operated 1,250 hours in the first year, 2,755 hours in the second year, and 1,225 hours in the third year of operations. Journalize the depreciation expense for each year