On January 1, Jefferson purchases a used machine for $130,000 and readies it for use the next day at a cost of $3.390. On January 4, is mounted on a required operating platform costing $4,800, and it is further readied for operations. Management estimates the machine will be used for seven years and have an $18,000 residual value. Depreciation is to be charged on a straight-line b On December 31, at end of its sixth year of use, the machine is disposed of.