Cosby uses a weighted average process-costing system. All materials are added at the beginning of the process; conversion costs are incurred evenly throughout production. The company finished 477 units during the period and had 137 units in progress at year-end, the latter at the 50% stage of completion. Total material costs amounted to $228,000; conversion costs were $448,000. The cost of goods completed is: Select one: a. $525,166 b. $600,583 c. $568,870 d. $676,000 e. $650,564