Derma Company applies overhead on the basis of direct labor hours in department B. Two direct labor hours are required for each product unit. Planned production for the period was budgeted at 9,000 units. Manufacturing overhead was budgeted at $135,000 for the period, 20% of this cost is fixed. The 17,200 hours worked during the period resulted in production of 8,500 units. Variable manufacturing overhead costs incurred were $108,500, and fixed manufacturing overhead costs were $28,000.

Required -

a. Compute the predetermined overhead rate that would have been used during the year, showing separately the variable and fixed components of the rate.

b. Calculate the over or under-applied overhead for the period.

c. Compute the variable overhead spending and efficiency variances and the fixed overhead budget and volume variances?

Please provide step by step for all