Gonzo Gasket Co. budgets 8,000 direct labor hours for the year. The total overhead budget is expected to amount to $20,000. The standard cost for a unit of the company's product estimates the variable overhead as follows:

Variable factory overhead (3 hours @ $2 per direct labor hour) . . . . $6 per unit

The actual data for the period follow:

Actual completed units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2,500

Actual direct labor hours . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7,640

Actual variable overhead . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $16,100

Actual fixed overhead . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3,920

Using the four-variance method, calculate the overhead variances.