Answer and Explanation:
The computation of the variable overhead rate variances is shown below:
As we know that
Variable overhead rate variance = (standard rate - actual rate) × actual hour
For Lubricants
Actual rate = $36,722 ÷ 8,180 machine hours = 4.48924
Now the variable overhead rate variance is
= ($4.30 - $4.48924) × 8,180 machine hours
= $1,548 Unfavorable
For Supplies
Actual rate = 24,112 ÷ 8,180 machine hours = $2.9476
Now the variable overhead rate variance is
= ($3 - $2.9476) × 8,180 machine hours
= $429 favorable
We simply applied the above formula