Assume that ExxonMobil uses a standard cost system for each of its refineries. For the Houston refinery, the monthly fixed overhead budget is $8,000,000 for a planned outputs of 5,000,000 barrels. For September, the actual fixed cost was $8,750,000 for 5,100,000 barrels. Required
a. Determine the fixed overhead budget variance.
b. If fixed overhead is applied on a per-barrel basis, determine the volume variance.
c. Provide formulas and an explanation.

a. Fixed overhead budget variance = Budgeted fixed overhead - Actual fixed overhead

= $8,000,000 - $8,750,000

= $750,000 Unfavorable

b. Predetermined overhead rate per barrel = $8,000,000 / 5,000,000

= $1.60 per barrel

Fixed overhead applied = 5,100,000 * $1.60

= $8,160,000

Fixed overhead volume variance = Fixed overhead applied - Budgeted fixed overhead  

= $8,160,000 - $8,000,000

= $160,000 Favorable

c. Fixed overhead budget variance = Budgeted fixed overhead - Actual fixed overhead

Predetermined overhead rate per barrel = Budgeted fixed overhead / Planned outputs

Fixed overhead volume variance = Fixed overhead applied - Budgeted fixed overhead