Parker Plastic, Incorporated, manufactures plastic mats to use with rolling office chairs, Its standard cost information for last year follows: Parker Plastic had the following actual results for the past yeor: Required: Caiculafe Parker Piastic's variable overhead rate and etficiency variances and its over- or underapplied variable oventead. Note: Do not round intermediate calculations. Indicate the effect of each variance by selecting "F* for faverable, "U" for unfavorable, and "None* for no effect (l.e., rero variance)