0.30 hours) per oil change. In July, 1,500 oil changes were performed at Campa Oil. Oil change technicians worked a total of 305 direct labor hours at an average rate of $23 per hour. Read the requirements. Requirement 1. Calculate the direct labor rate variance. the formula to the nearest cent, then round the final variance amount to the nearest whole dollar. Abbreviations used: DL = Direct labor.) Requirement 2. Calculate the direct labor efficiency variance. amount in the formula to the nearest cent, then round the final variance amount to the nearest whole dollar. Abbreviations used: DL = Direct labor.)