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 2

Standard overhead rate per DL hour $6.50

Standard overhead cost per unit $13.00

Actual overhead costs $17,200

Actual DL hours 2150

Actual overhead cost per machine hour $8.00

Actual tubs produced 1100

What is the variable manufacturing overhead rate variance in March?