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 $ 4.50
Standard variable overhead cost per unit $ 22.50
Actual variable overhead costs $ 30,375
Actual DL hours 4,050
Actual variable overhead cost per machine hour $ 7.50
Actual tubs produced 1,000
1. What is the variable manufacturing overhead rate variance in​ March?