Final answer:
The flexible budget variance for fixed manufacturing OH is the same as the spending variance because fixed costs do not change with production levels; variances arise only from differences in actual versus budgeted expenditure, not activity volume.
Step-by-step explanation:
The flexible budget variance for fixed manufacturing overhead (OH) is identical to the spending variance because fixed costs do not fluctuate with the level of production. As such, the main distinctions seen in flexible budget variance, which generally relate to changes in activity levels, are not present with fixed manufacturing overhead. The fixed nature of these costs means that the variance, if any, would come from a difference in what was actually spent versus the budgeted amount, not from changes in production volume.
For example, if a company has budgeted for $10,000 in fixed manufacturing overhead for machinery rent, and the actual rent paid is $10,000, there would be no flexible budget variance nor spending variance, because the amount is fixed and does not change regardless of the production volume. If, however, the actual rent paid is $11,000, the flexible budget variance and the spending variance would both be $1,000 unfavorable, because the fixed cost exceeded what was budgeted. This scenario illustrates that the variance arises from the spending side, not the production volume side.