Denominator level of activity 1,600 machine-hours Budgeted fixed manufacturing overhead costs $42,400 Fixed portion of the predetermined overhead rate $26.50 per machine-hour Actual level of activity 1,700 machine-hours Standard machine-hours allowed for the actual output 2,000 machine- hours Actual fixed manufacturing overhead costs $41,740 Required: a. Compute the budget variance for September. Show your work! b. Compute the volume variance for September.