All Fixed Overhead Company computes its overhead rate based on a standard level of output of 20,000 units. Fixed manufacturing overhead for the current year is budgeted at USD 30,000. Actual fixed manufacturing overhead for the current year was USD 31,000. Overhead is applied based on units produced. Compute the amount of overhead volume variance for the year under each of the following assumptions regarding actual output:

a. 12,500 units.

b. 22,500 units.