Parker Plastic, Incorporated, manufactures plostic mats to use with rolling office chairs. Its standard cost information for last year foulowe: Parker Plastic had the following actual results for the past year: Required: Required: Calculate Parker Plastic's variable overhead rate and efficlency variances and its over- or underapplied variable overhead. Note: Do not round intermedlate calculations. Indicate the effect of each variance by selecting "F" for favorable, "U" for unfavorable, and "None" for no effect (i.e., zero variance)