Trini Company set the following standard costs per unit for its single product.

Overhead is applied using direct labor hours. The standard overhead rate is based on a predicted activity level of $80\%$ of

the company's capacity of $60,000$ units per quarter. The following additional information is available.

During the current quarter, the company operated at $90\%$ of capacity and produced $54,000$ units; actual direct labor

totaled $265,000$ hours. Units produced were assigned the following standard costs.

Actual costs incurred during the current quarter follow.

Required:

$($a$)$ Compute the variable overhead spending and efficiency variances.

$($b$)$ Compute the fixed overhead spending and volume variances.

$($c$)$ Compute the overhead controllable variance.