Answer:
  Variable overhead efficiency variance $ 8,018
<u> </u>Unfavorable 
Explanation:
<em>Variable overhead efficiency variance: Variable overhead efficiency variance aims to determine whether or not their exist savings or extra cost incurred on variable overhead as a result of workers being faster or slower that expected.  </em>
Since the variable overhead is charged using labour hours, any amount by which the actual labour hours differ from the standard allowable hours would result in a variance  
                                                                                       Hours 
2,700 units should have taken (2,700 × 3.20)           8640
but did take  (actual hours)                                   <u>      9,400</u>
Efficiency variance in hours                                      760 unfavorable
 standard variable overhead cost per hour           <u>$10.55</u>
Variable overhead efficiency variance                  $<u> 8,018  </u>Unfavorable
  Variable overhead efficiency variance $ 8,018
<u> </u>Unfavorable