Rathburn, Inc. is a service firm that uses process costing. The firm worked on a total of 1500 cases this month, 1400 of which were completed during the period. The remaining cases were 30% complete. The firm incurred $366,600 in direct labor and manufacturing overhead costs during the period, and had $5200 in direct labor and manufacturing costs in beginning inventory. Using the weighted average method, what was the total cost of cases completed during the period?

$364,000

$85,200

$8520

$7800