Cinturon Corporation produces high-quality leather belts. The company's plant in Boise uses a standard costing system and has set the following standards for materials and labor: During the first month of the year, the Boise plant produced 92,000 belts. Actual leather purchased was 287,500 strips at $3.60 per strip. There were no beginning or ending inventories of leather. Actual direct labor was 78,600 hours at $18.50 per hour. Required: 1. Break down the total variance for labor into a rate variance and an efficiency variance using the columnar and formula approaches