Handerson Corporation makes a product with the following standard costs: Standard Quantity or Standard Price or Hours Rate $ 6.00 per kilo $20.00 per hour $ 6.00 per hour 8.5 kilos Direct materials Direct labor 0.4 hours Variable overhead 0.4 hours The company reported the following results concerning this product in August Actual output Raw materials used in production Purchases of raw materials 3,200 units 29,030 kilos 31,600 kilos 1,160 hours Actual direct labor-hours Actual cost of raw materials $195,920 purchases Actual direct labor cost $22,736 $ 7,540 Actual variable overhead cost The company applies variable overhead on the basis of direct labor-hours. The direct materials purchases variance is computed when the materials are purchased. The variable overhead rate variance for August is: Multiple Choice $580 F $640 F $580 U $640 U