The following standards for variable overhead have been established for a company that makes only one product: Standard hours per unit of output 3.6 hours Standard variable overhead rate $16. 05 per hour The following data pertain to operations for the last month: Actual hours 5, 000 hours Actual total variable overhead cost $80, 000 Actual output 1, 300 units Required: a. What Is the variable overhead rate variance for the month? b. What is the variable overhead efficiency variance for the month