World Company expects to operate at 80% of its productive capacity of 56,250 units per month. At this planned level, the company expects to use 22,500 standard hours of direct labor. Overhead is allocated to products using a predetermined standard rate of 0.500 direct labor hour per unit. At the 80% capacity level, the total budgeted cost includes $60,750 fixed overhead cost and $263,250 variable overhead cost. In the current month, the company incurred $338,000 actual overhead and 19,500 actual labor hours while producing 42,000 units. Required:
a. Compute the overhead volume variance.
b. Compute the overhead controllable variance.