Ravena Labs., Incorporated makes a single product which has the following standards:

Direct materials: $2\mathrm{.}5$ ounces at $$20$ per ounce

Direct labor: $1\mathrm{.}4$ hours at $$12\mathrm{.}50$ per hour

Variable manufacturing overhead: $1\mathrm{.}4$ hours at $3\mathrm{.}50$ per hour

Variable manufacturing overhead is applied on the basis of standard direct labor$-$hours. The following data are available for October:

$3,750$ units of compound were produced during the month.

There was no beginning direct materials inventory.

Direct materials purchased: $12,000$ ounces for $$225,000.$

The ending direct materials inventory was $2,000$ ounces.

Direct labor$-$hours worked: $5,600$ hours at a cost of $$67,200.$

Variable manufacturing overhead costs incurred amounted to $$18,200.$

Variable manufacturing overhead applied to products: $$18,375.$

The variable overhead efficiency variance for October is: