NSF Lube is a fast-growing chain of oil-change stores. The following data are available for last year's services: .NSF Lube performed 470,700 oil changes last year. It had budgeted 433,800 oil changes, averaging 13 minutes each. . Standard variable labor and support costs per oil change were as follows: Direct oil specialist services: 13 minutes at $24 per hour $20 Variable support staff and overhead: 9.0 minutes at $20 per ,0 hour . Fixed overhead costs: Annual budget $1,037,800 . Fixed overhead is applied at the rate of $3.30 per oil change Actual oil change costs: Direct oil specialist services: 470,700 changes averaging 16 minutes at $27 per hour 40 Variable support staff and overhead: 0.16 labor-hours at $15 per hour x 470,700 changes Fixed overhead 1.12980 1.335,000 Required: a. Prepare a cost variance analysis for each variable cost for last year. (Do not round intermediate calculations. Indicate the effect of each variance by selecting "F for favorable, or "U" for unfavorable. If there is no effect, do not select either option.) b. Prepare a fixed overhead cost variance analysis. (Indicate the effect of each variance by selecting "F" for favorable, "U" for unfavorable, and "None" for no effect.) overtead cost wanne