Marvel Parts Inc. manufactures auto accessories. One of the company's products is a set of seat covers that can be adjusted to t nearly any small car. The companyI has a standard cost system in use for all of its products. According to the standards that have been set for the seat covers, the factory should work 1,055 hours each month to produce 2,110 sets of covers. The standard costs associated with this level of production are as follows: Per Set Total of Cover! Direct materials $ 51,2?3 $24.30 Direct labour $ 10,550 5.00 Variable manufacturing overhead (based on direct. labour-hours} $ 4,553 2.30 $31.50 During August, the factory worked only 1,000 direct labour-hours and produced 2,100 sets of covers. The following actual costs were recorded during the month: For Set Total of Cover! Direct materials {6,300 yards} $ 49,930 $23.30 Direct labour $ 10,920 5.20 Variable manufacturing overhead $ 5, 460 2 .50 $ 3 1 . 50 At standard, each set of covers should require 3.00 yards of material. All of the materials purchased during the month were used in production. 3. Compute the variable overhead rate and efficiency variances for August. (Input all amounts as positive values. Indicate the effect of each variance by selecting "F" for favorable, "U" for unfavorable, and "None" for no effect (i.e, zero variance).) Variable overhead rate variance Variable overhead efficiency variance