Gordon Enterprises gathered the following information for the month of July: Overhead flexible budget:

Number of units: 3,000 4,000 5,000

Standard machine hrs: 12,000 16,000 20,000

Budgeted overhead costs:

Variable $27,000 $36,000 $45,000

Fixed $51,000 $51,000 $60,000

Gordon actually produced 4,000 units in 16,400 machine hours. Total actual overhead cost of $82,000 consisted of $33,00 variable costs and $49,000 fixed costs. The standard variable and fixed overhead rates are based on a master (static) budget of 3,000 units.

a) Compute the total manufacturing overhead cost variance.

b) Compute the overhead flexible budget variance.

c) Compute the production volume variance.