Solly Corporation produces a product for national distribution. Standards for the product are: Materials: 12 ounces per unit at 60 per ounce. Labor: 2 hours per unit at $8 per hour. During the month of December, the company produced 1,000 units. Information for the month follows: Materials: 14,000 ounces purchased and used at a total cost of $7,700. Labor: 2,500 hours worked at a total cost of $20,625. The labor efficiency variance is: