Answer:
variable overhead efficiency variance= $562.5 unfavorable
Explanation:
Giving the following information:
The actual production of 5,500 units 
Actual direct labor hours= 11,250 
Standard direct labor for 5,500 units: 
Standard hours allowed 11,000 hours 
First, we need to determine the variable overhead rate:
Variable overhead rate= 22,500/10,000= $2.25 per direct labor hour
Now, using the following formula we can determine the variable overhead efficiency variance:
variable overhead efficiency variance= (Standard Quantity - Actual Quantity)*Standard rate
variable overhead efficiency variance= (11,000 - 11,250)*2.25
variable overhead efficiency variance= $562.5 unfavorable