Can someone provide step-by-step solutions to the problem? I provided the correct answer from my textbook so that you can check your answer. Thanks in advance!

7. Minimizing inventory costs. A snowmobile dealer in Minnesota expects to sell 960 snowmobiles during the next year. It costs $9 to store one snowmobile for one year. To reorder, there is a fixed cost of $67.50, plus $7.50 for each snowmobile. In what lot size and how many times per year should an order be placed to minimize inventory costs?7. 120 snowmobiles per order; 8 orders per year