Answer
The increase in net operating income= Number increase in units $\times$ Contribution margin per unit = 1 $\times$ 8 = $8
Work Step by Step
Number increase in units = 1,001 - 1,000 = 1 (unit)
Contribution margin per unit = $8 (Calculated in question 1)
Because contribution margin per unit shows us the amount of revenue from the sale of one unit after covering the variable expenses, the increase in net operating income would be equal to multiplying the number increase in units with the contribution margin per unit.
