The following labor standards have been established for a particular product: Standard labor-hours per unit of output 9.4 hours Standard labor rate $13.20 per hour The following data pertain to operations concerning the product for the last month: Actual hours worked 7,200 hours Actual total labor cost $92,160 Actual output 1,050 units What is the labor efficiency variance for the month? $38,124 F $38,124 U $34,176 F $35,244 F