The following labor standards have been established for a particular product: Standard labor-hours per unit of output Standard labor rate 9 hours $12.80 per hour The following data pertain to operations concerning the product for the last m 9 ont h: Actual hours worked Actual total labor cost $84,320 Actual output 6, 800 hours 800 units What is the labor efficiency variance for the month? Multiple Choice $4,960 F $7,840 F $5.120 ok Multiple Choice $4,960 F $7840 F $7.840 F $5,120 F C)$7840 U