Sheffield Company's overhead rate was based on estimates of $1,238,400 for overhead costs and 103,200 direct labor hours. Sheffield's standards allow 5 hours of direct labor per unit produced. Production in May was 1,742 units, and actual overhead incurred in May was $105,370. The overhead budgeted for 8,710 standard direct labor hours is $104,080 ( $34,400 fixed and $69,680 variable). (a) Compute the total, controllable, and volume variances for overhead