Parker Plastic, Incorporated, manufactures plastic mats to use with rolling office chairs. Its standard cost information for last year follows: Standard Quantity Standard Price (Rate) Standard Unit Cost Direct materials (plastic) 14 square foot $ 0.80 per square foot $ 11.20 Direct labor 0.25 hour $ 12.40 per hour 3.10 Variable manufacturing overhead (based on direct labor hours) 0.25 hour $ 1.60 per hour 0.40 Fixed manufacturing overhead ($519,680 928,000 units) 0.56 Parker Plastic had the following actual results for the past year: Number of units produced and sold 1,220,000 Number of square feet of plastic used 12,300,000 Cost of plastic purchased and used $ 8,610,000 Number of labor hours worked 326,000 Direct labor cost $ 3,912,000 Variable overhead cost $ 1,240,000 Fixed overhead cost $ 383,000 Required: Calculate Parker Plastics variable overhead rate and efficiency variances and its over- or underapplied variable overhead. Note: Do not round intermediate calculations. Indicate the effect of each variance by selecting "F" for favorable, "U" for unfavorable, and "None" for no effect (i.e., zero variance).