Roll Corporation manufactures a single product. The standard cost per unit of product is as follows. Direct materials -2 pounds of plastic at $6 per pound $12 The master manufacturing overhead budget for the month based on normal productive capacity of 20,000 direct labor hours (10,000 units) shows total variable costs of $70,000($3.50 per labor hour) and total fixed costs of $50,000 ( $2.50 per labor hour). Normal productive capacity is 20,000 direct labor hours. Overhead is applied on the basis of direct labor hours. Actual costs for November in producing 9,700 units were as follows. Direct materials ( 20,000 pounds) $119,000 Direct labor (19,600 hours) 256,760 Variable overhead 68,800 Fixed overhead 50,000 Total manufacturing costs $494,560 The purchasing department normally buys the quantities of raw materials that are expected to be used in production teach month. Raw materials inventories, therefore, can be ignored. Instructions (a) Compute all of the materials and labor variances. (b)Compute the total overhead variance