Riverside manufacturing designs and manufactures bathtubs for home and commercial applications. riverside recorded the following data for its commercial bathtub production line during the month of march:
standard dl hours per tub 5
standard variable overhead rate per dl hour $ 6.00
standard variable overhead cost per unit $ 30.00
actual variable overhead costs $ 16,400
actual dl hours 2,050
actual variable overhead cost per machine hour $ 8.00
actual tubs produced 1,500
1. what is the variable manufacturing overhead efficiency variance in march?