Edelman Oil performs oil changes. The standard wage rate for oil change technicians is $$17$ per hour. By analyzing its past records of time spent on oil changes, the company has developed a standard of $18$ minutes $($or $0\mathrm{.}30$ hours$)$ per oil change.In July, $1,600$ oil changes were performed at Edelman Oil. Oil change technicians worked a total of $310$ direct labor hours at an average rate of $$24$ per hour.Requirements Calculate the direct labor rate variance.Calculate the direct labor efficiency variance.