Kropf Inc. has provided the following data concerning one of the products in its standard cost system. Variable manufacturing overhead is applied to products on the basis of direct labor-hours. Inputs: Direct materials Direct labor Variable manufacturing overhead Standard Quantity or Hours per Unit of Output 8.00 liters 0.70 hours 0.70 hours Standard Price or Rate. $ 7.60 per liter $19.70 per hour $ 6.50 per hour The company has reported the following actual results for the product for September: Actual output Raw materials purchased Actual cost of raw materials purchased Raw materials used in production Actual direct labor-hours Actual direct labor cost Actual variable overhead cost 10,200 units 82,600 liters $646,500 81,630 liters 6,600 hours: $138,302 $35,314 Required: a. Compute the materials price variance for September. b. Compute the materials quantity variance for September. c. Compute the labor rate variance for September. d. Compute the labor efficiency variance for September. e. Compute the variable overhead spending variance for September. f. Compute the variable overhead efficiency variance for September. (Indicate the effect of each variance by selecting "F" for favorable, "U" for unfavorable, and "None" for no effect (i.e., zero variance). Input all amounts as positive values.) a Materials price variance b. Materials quantity variance Labor rate variance d Labor efficiency variance)