Dubberly Corporation's cost formula for its manufacturing overhead is $30,700 per month plus $60 per machine-hour. For the month of March, the company planned for activity of 7,920 machine-hours, but the actual level of activity was 7,890 machine- hours. The actual manufacturing overhead for the month was $528,430. The activity variance for manufacturing overhead in March would be closest to: Multiple Choice $1,80 $22,53 $1,800 $22,530F