To solve this problem, we should recall the spending variance is expressed as:
Spending variance = Actual results - Flexible budget
Where,
Spending variance = $ 2,261 Unfavorable
Actual results = $ 31,178
Flexible budget = 11,900 X
X represents the cost formula per machine-hour for indirect materials. Substituting the values to the equation:
2,261 = 31,178 - 11,900 X
- 11,900 X = - 28,917
X = $ 2.43 (ANSWER)