Mongar Corporation applies manufacturing overhead to products on the basis of standard machine-hours. Budgeted and actual overhead costs for the most recent month appear below: Original Budget Actual Costs Variable overhead costs: Supplies $ 7,980 $ 8,230 Indirect labor 29,820 29,610 Total variable manufacturing overhead cost $ 37,800 $ 37,840 The original budget was based on 4,200 machine-hours. The company actually worked 4,350 machine-hours during the month and the standard hours allowed for the actual output were 4,190 machine-hours. What was the overall variable overhead efficiency variance for the month