The variable overhead rate variance for January is:

A) $91 F
B) $87 F
C) $91 U
D) $87 U

Variable overhead rate variance = AH × (AR − SR)
= 910 hours × ($7.90 per hour − $8.00 per hour)
= 910 hours × (−$0.10 per hour)
= $91 F
Reference: CH09-Ref78
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