Vermeillen Corporation uses a standard costing system in which variable manufacturing overhead is assigned to production on the basis of the number of machine setups. The following data pertain to one month's operations: . Variable manufacturing overhead cost incurred: $70,000 Total variable manufacturing overhead variance: $4,550 Favorable Standard machine setups allowed for actual production: 3,550 Actual machine setups incurred: 3,500 The variable overhead rate variance is: . . O $3,500 Favorable O $3,500 Unfavorable $1,000 Favorable $1,000 Unfavorable