The Maxit Corporation has a standard costing system in which variable manufacturing overhead is assigned to production on the basis of standard machine$-$hours. The following data are available for July:

Actual variable manufacturing overhead cost incurred: $$25,040$

Actual machine$-$hours worked: $2,700$ hours

Variable overhead rate variance: $$5,070$ U

Total variable overhead spending variance: $$7,040$ U

The variable overhead efficiency variance for July is: