Cordele Company purchased equipment on January 1, 2018, at a total invoice cost of $800,000. The equipment has an estimated salvage value of $20,000 and an estimated useful life of 5 years. What is the amount of accumulated depreciation at December 31, 2019, if the straight-line method of depreciation is used? $160,000 $320,000 $156,000 $312,000