Parker Plastlc, Incorporated, manufactures plastic mats to use with rolling office chalrs. Its standard cost information for last year follows: Parker Plastic had the following actual results for the past year: Required: Calculate Parker Plastlc's varlable overhead rate and efficlency varlances and Its over- or underapplied varlable overhead. Note: Do not round Intermedlate calculations. Indlcate the effect of each varlance by selecting "F" for favorable, "U" for unfavorable, and "None" for no effect (l.e., zero varlance)