Answer:
Effect on income= $4,400 increase
Explanation:
Because it is a special order and there is unused capacity, we will not take into account the fixed costs.
To calculate the effect on income, we need to use the following formula:
Effect on income= number of units*unitary contribution margin
Effect on income= 4,400 (21 - 18 - 2)
Effect on income= $4,400 increase