Stella was planning for Halloween as she placed orders for fun decorations and other items to celebrate the holiday. Last year she had a run on skeleton-themed items and ended up stocking out. This year she decided to order an extra 20% more of the skeleton-themed items in hopes of not stocking out. However, she is also running the risk of having too many leftover at the end of October. Stella is using the ____________________. single-period inventory model EOQ model fixed-quantity inventory system fixed-period inventory system