Wisteria Co. produces snowboards and uses a standard cost system. Variable overhead is applied using direct labor hours. Standards allowed for each unit are 5.3 hours of labor at a standard variable overhead rate of $7.20. During December, Wisteria Co. produced 3,000 snowboards. Materials purchases totaled 21,500 pounds at a total cost of $224,780. Materials usage totaled 21,060 pounds. Payroll totaled $183,730 for 17,130 hours worked. Variable overhead incurred totaled $120,466. a. Calculate the variable overhead rate variance. (Do not round your intermediate calculations. Indicate the effect of variance by selecting "Favorable", "Unfavorable", or "None" for no effect (i. e., zero variance).)