The following standards for variable manufacturing overhead have been established for a company that makes only one product:

Standard hours per unit of output	8.0	hours
Standard variable overhead rate	$14.40	per hour

The following data pertain to operations for the last month:

Actual hours	2,850	hours
Actual total variable manufacturing overhead cost	$41,770
Actual output	200	units

What is the variable overhead efficiency variance for the month?