Shade Company adopted a standard cost system several years ago. The standard costs for direct labor and direct materials for its single product are as follows: Materials (5 kilograms $12.00 per kilogram) = $60.00 per unit; direct labor (3.5 hours per unit $20.00 per hour) = $70.00 per unit. All materials are issued at the beginning of processing. The operating data shown below were taken from the records for December: In-process beginning inventory None In-process ending inventory80% complete as to labor 960 units Units completed during the period 6,700 units Budgeted output 7,200 units Purchases of materials (in kilograms) 40,000 Total actual direct labor cost incurred $ 528,410 Direct labor hours worked (AQ) 26,500 hours Materials purchase-price variance $ 1,600 favorable Increase in materials inventory in December 1,550 kilograms The direct labor rate variance for December was: