Answer:
$650
Explanation:
To calculate the variable overhead efficiency variance we start with the standard variable machine cost of $5. We then have to work out the amount of machine hours required for 410 chairs. This is 1230 (410 x 3). We actually only used 1100 hours to produce 410 chairs. We now use the formula, namely; standard variable rate x (actual hours-standard hours).
5 x (1100-1230)
= $650 favorable as we used less hours than the standard amount of hours for the chairs produced