Belle Auto Detailing reported the following results for the past week: Actual number of cars detailed Actual direct labor hours used Actual total direct labor cost 110 275 $6800 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? 280 $8.46 1.5 $931 unfavorable $2720 unfavorable $931 favorable $2720 favorable