c$.$ Incorporated, manufactures plastic mats to use with rolling office chairs. Its standard cost information for last year

rker Plastic's variable overhead rate and efficiency variances and its over$-$ or underapplied variable overhead.

$t$ round intermediate colculations. Indicate the effect of each variance by selecting $"$F$"$ for favorable, $"U"$ for $.$ and "None" for no effect $($i$.$e$.,$ zero variance$).$