NSF Lube is a fast-growing chain of oil-change stores. The following data are available for last years services. NSF Lube performed 467,700 oil changes last year. It had budgeted 435,000 oil changes, averaging 8 minutes each. Standard variable labor and support costs per oil change were as follows. Direct oil specialist services: 8 minutes at $30 per hour $ 4.00 Variable support staff and overhead: 10.5 minutes at $20 per hour 3.50 Fixed overhead costs: Annual budget $1,039,000 Fixed overhead is applied at the rate of $2.40 per oil change. Actual oil change costs: Direct oil specialist services: 467,700 changes averaging 11 minutes at $34 per hour $ 2,915,330 Variable support staff and overhead: 0.22 labor-hours at $15 per hour 467,700 changes 1,543,410 Fixed overhead 1,425,000 Required: a. Prepare a cost variance analysis for each variable cost for last year. b. Prepare a fixed overhead cost variance analysis.