Answer: Monthly operating income will decrease by $5400.
Explanation:
Volume = 1200 units per month
Variable cost per unit = $11.50 per unit
Fixed costs = $10,000 per month
Since Cheong decides to outsource, the monthly operating income will be calculated thus:
= Volume × (Cost of ready made units - Variable cost per unit)
= 1200 × (16 - 11.50)
= 1200 × 4.50
= $5400
Therefore, the monthly operating income will decrease by $5400.