The following labor standards have been established for a particular product: Standard labor hours per unit of output 8.6hours Standard labor rate 12.40per hour The following data pertain to operations concerning the product for the last month: $ 6400hours 76,800 850units Actual hours worked Actual total labor cost Actual output What is the labor efficiency variance for the month? $11.284 F $10.920 F $13,844 F $13,844 U