Cullumber's Repair Service uses the straight-line method of depreciation. The company's fiscal year-end is December 31. The following transactions and events occurred during the first three years. 2021 July 1 Purchased equipment from the Equipment Center for $6,700 cash plus sales tax of $430, and shipping costs of $300. Nov. 3 Incurred ordinary repairs on computer of $250. Dec. 31 Recorded 2021 depreciation on the basis of a four-year life and estimated salvage value of $590. 2022 Dec. 31 Recorded 2022 depreciation. 2023 Jan. 1 Paid $4,200 for a major upgrade of the equipment. This expenditure is expected to increase the operating efficiency and capacity of the equipment