Belle Auto Detailing reported the following results for the past week: 110 Actual number of cars detailed Actual direct labor hours used Actual total direct labor cost 275 $6800 280 $8.46 Budgeted number of cars to be detailed Standard direct labor cost per hour Standard direct labor per car What is Belle's direct labor efficiency variance? $2720 unfavorable $2720 favorable $931 favorable $931 unfavorable