Austin Company applies overhead on the basis of direct labor hours.

Here is the information provided to you by the Controller. Standards: FOH (3 DLH) Planned production: 8,000 units. Budgeted factory overhead: $72,000 Budgeted fixed factory overhead: $48,000 Actual Hours Worked: 25,000 Actual Units Made: 8,500 units. Actual manufacturing overhead cost incurred: $80,000. Required: Calculate the following:

a. Total Spending Variance

b. Total Efficiency Variance

c. Total Volume Variance

d. Proof