regarding the Question 5 and 7, I have apply the step of the book "Manufacturing planning and control for supply chain management" Chapter 9.

applying the steps don't lead to the correct answers. because in the book we use the average inventory (beginning+ending inventory)/2 to calculate the holding cost.

I have made some research in others resources and I find that they use the ending inventory to calculate the cost and when I used this method I have found the corrects answers.

Could you please help me, why we should use the ending inventory and not the average inventory to calculate the holding cost?

APICS/CPIM Certification Questions | 295 4 6 7 4. Given the following values, what is the economic order quantity (EOQ)? Cp = 100, D=1000, Gh=10 (Choose the nearest answer.) a. 10 b. 100 c. 250 d. 1,000 5. Given the following demand pattern and system costs, what is the total cost for an economic order quantity (EOQ) lot-sizing policy? (Choose the nearest value.) C $1,500.00 CH $ 2.00 Week number 1 2 3 5 9 9 10 11 12 Requirements 500 400 750 600 900 550 450 325 500 725 650 700 Order quantity Beginning inventory Ending inventory a $20,000 b. $22.000 c. $24,000 d. $26,000 6. Given the following values, what is the time between orders (TBO) when using a periodic order quantity (POQ) lot-sizing policy? Cp= 100, D = 4, CH = 10 (Choose the nearest value.) a. 1 b. 1.5 C. 2 d. 3 7. Given the following demand pattern and system costs, what is the total cost for a Periodic order quantity (POQ) lot-sizing policy? (Choose the nearest value.) $1,500.00 $ 2.50 8 9 10 11 12 100 145 130 140 1 2 3 4 -5 6 2 150 120 180 110/90 65 100 80 Week number Requirements Order quantity Beginning inventory Ending inventory