Fixed costs had no budget variances . Prepare an overhead performance report for May. Include both fixed and variable costs in your report ( in Separate Sections ) . Structure your report so that it Shows only a spending variance for overhead . The company originally budgeted to work 40, 000 machine- hours during the month ; Standard hours allowed for the month's production totaled 41, 000 machine - hours . (10 mark's ) J. Explain possible causes of the spending variance for supplies . ( 10 marks ) E. Compute an efficiency variance for total variable overhead cost , and explain the nature of the variance . ( 10 mark's )