E$9-10($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:

$\backslash$table$[[,,,],[,$Standard Quantity,Standard Price $($Rate$),$Cost$],[$Direct materials $($plastic$),13$ square foot,$$1\mathrm{.}55$ per square foot,$$20\mathrm{.}15$