Zimmerman Corporation uses a standard cost system for the production of its radios. The direct labor standard for each radio is 0.9 hours. The standard direct labor cost per hour is $7.20. During the month of August, Zimmerman's radio production used 6,900 direct labor-hours at a total direct labor cost of $47,520. This resulted in production of 6,700 radios for August. What is Zimmerman's labor rate variance for August? $720 Favorable $1,440 Unfavorable $2,160 Favorable $6,264 Unfavorable