The predetermined manufacturing overhead rate is $10.00 per direct labor hour ($16.00 ÷ 1.6). It was computed from a master manufacturing overhead budget based on normal production of 8,000 direct labor hours (5,000 units) for the month. The master budget showed total variable costs of $60,000 ($7.50 per hour) and total fixed overhead costs of $20,000 ($2.50 per hour). The actual costs for October in producing 4,800 units were as follows.
 Direct materials (5,100 pounds) $ 36,720
 Direct labor (7,400 hours) 92,500
 Variable overhead 59,700
 Fixed overhead 21,000
  Total manufacturing costs $209,920
 The purchasing department buys the quantities of raw materials that are expected to be used in production each month. Raw materials inventories, therefore, can be ignored.
 a. Compute all of the materials and labor variances. (Round answers to 0 decimal places, e.g. 125.)
 b. Compute the total overhead variance.