Sheffield Company's overhead rate was based on estimates of $194,400 for overhead costs and 19,440 direct labour hours. Sheffield's standards allow 2 hours of direct labour per unit produced. Production in May was 860 units, and actual overhead incurred in May was $19,000. The overhead budgeted for 1,720 standard direct labour hours is $16,900 ($4,860 fixed and $12,040 variable). (a) Calculate the total, budget, and volume variances for overhead. Total overhead variance Overhead budget variance Overhead volume variance $