E9-10 (Algo) Calculating Variable Overhead Variances [LO 9.5] 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 year Requiredt Calculate Parker Plastic's variable overheod 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 unfovorable, and "None" for no effect (Le., zero variance)