Bulluck corporation makes a product with the following standard costs: standard quantity or hours standard price or rate direct materials 5.20 grams $ 2.70 per gram direct labor 0.70 hours $ 28.00 per hour variable overhead 0.70 hours $ 3.70 per hour the company reported the following results concerning this product in july. actual output 4,700 units raw materials used in production 13,070 grams actual direct labor-hours 3,060 hours purchases of raw materials 13,800 grams actual price of raw materials purchased $ 2.90 per gram actual direct labor rate $ 13.10 per hour actual variable overhead rate $ 3.80 per hour the company applies variable overhead on the basis of direct labor-hours. the direct materials purchases variance is computed when the materials are purchased. the variable overhead efficiency variance for july is: