The following labor standards have been established for a particular product: Standard labor hours per unit of output 4.0 hours Standard labor rate $ 17.70 per hour The following data pertain to operations concerning the product for the last month: Actual hours worked 7,600 hrs Actual total labor cost $135,280 Actual output 1,800 units Required: a. What is the labor efficiency variance for the month? b. Label the variance unfavorable or favorable. Please include numbers used for calculations and label the variances