Russo Corporation manufactured 21,000 air conditioners during November. The overhead cost-allocation base is $34.25 per machine-hour. The following variable overhead data pertain to November: Production Machine-hours Variable overhead cost per machine-hour Actual 21,000 units 13,300 hours $34.00 Budgeted 24,000 units 14,400 hours $34.25 What is the variable overhead spending variance