The Sterling Company uses a standard cost system in which manufacturing overhead costs arc applied to the units of the company's single product on the basis of direct labor -hours (DLI Is). The standard cost card for the product follows: Standard Cost Card -per unit of product: Direct materials, 4 yards at $3.50 per yard $14 Direct labor, 1.5 DLL Is at $8 per DLIA 12 Variable overhead, 1.5 DU Is at $2 per DLH 3 The following data pertain to last year's activities: - The company manufactured 18,000 units of product during the year. A total of 70,200 yards of material was purchased during the year at a cost of $3.75 per yard. All of this material was used to manufacture the 18,000 units. - The company worked 29,250 direct labor hours during the year at a cost of $7.80 per hour. - Actual variable manufacturing overhead costs were S61,425. Required (IS points): a. Compute the direct materials price and quantity variances for the year. b. Compute the direct labor rate and efficiency variances for the year. c. Compute the variable overhead flue and efficiency variances for the year. d. Discuss some possible reasons for the direct labor variances that you computed