Final answer:
The approximate production order quantity for this problem is 894 units.
Step-by-step explanation:
To calculate the production order quantity, we can use the EOQ formula: EOQ = √((2 * Annual Demand * Setup Cost) / Holding Cost).
Given that the annual demand is 4,000 units, the setup cost is $100, and the holding cost is $20 per unit per year, we can substitute these values into the formula:
EOQ = √((2 * 4000 * 100) / 20) = √(800000) ≈ 894.43
Rounding to the nearest whole number, the approximate production order quantity for this problem is 894 units.