activity is expressed in machine hours with point v indicating the standard hours re 630992

Items 1 and 2 are based on the following:

The diagram below depicts a factory overhead flexible budget line DB and standard overhead application line OA. Activity is expressed in machine hours with Point V indicating the standard hours required for the actual output in September 2005. Point S indicates the actual machine hours (inputs) and actual costs in September 2005.

Are the following overhead variances favorable or unfavorable?

The budgeted total variable overhead cost for C machine hours is

1. AB
2. BC
3. AC minus DO
4. BC minus DO