Gateway Company has determined annual demand for its rollerblades is $4,000$ units.The cost of each rollerblade is $$80,$ and the inventory carrying cost is estimated to be $10\%$ of the cost of each rollerblade. Gateway Company has determined that the average ordering cost is $$10$ perorder. Furthermore, it takes about two weeks for an order to arrive from the supplier, and during this time, the demand per week for rollerblades is approximately $40$ units.