The Maxwell Corporation has a standard costing system in which variable manufacturing overhead is assigned to production on the basis of standard machine-hours. The following data are available for July:

Actual variable manufacturing overhead cost incurred: $25,700

Actual machine-hours worked: 3,000 hours

Variable overhead rate variance: $5,520 Unfavorable

Total variable overhead spending variance: $7,700 Unfavorable

The variable overhead efficiency variance for July is:

$13,220 Unfavorable

$13,220 Favorable

$2,180 Unfavorable

$2,180 Favorable