Jumpers Inc. manufactures parachutes. Fixed and variable manufacturing cost pools are allocated to each parachute using budgeted assembly hours. Budgeted assembly time is 4 hours per unit. The following table presents the amounts for July. Actual Static Results Budget Number of parachutes produced 260 240 Hours of assembly time 988 Variable overhead cost per hour $28 Variable overhead cost $34,580 Fixed manufacturing overhead cost $19,800 $20,160 Required: a. Calculate the efficiency variance for variable overhead costs. b. Calculate the rate variance for variable overhead costs. C. Calculate the rate variance for fixed overhead costs