4. Amnesty Elements uses a standard cost system, applying manufacturing overhead c basis of machine hours. The company's overhead standards per unit are shown below. Variable overhead: 4 hours at $9 per hour Fixed overhead: 4 hours at $6 per hour "Based on planned monthly activity of 120,000 machine hours Actual data for May were: Number of units produced: 29,000 Number of machine hours worked: 125,000 Variable overhead costs incurred: $1,085,000 Fixed overhead costs incurred: $755,000 Required: (10 points) A. Calculate the spending and efficiency variances for variable overhead. B. Calculate the budget and volume variances for fixed overhead