The following labor standards have been established for a particular product: Standard labor-hours per unit of output 9 hours Standard labor rate $12.80 per hour The following data pertain to operations concerning the product for the last month: Actual hours worked 6, 800 hours Actual total labor cost $84, 320 Actual output 800 units What is the labor efficiency variance for the month? Multiple Choice O $7,840 U O $4,960 F