Could anyone help me to solve this question by using inventory method in business decision mode?

The average daily customer demand for the Q shop is normally distributed, with a mean monthly demand of 45 items and a standard deviation of 8 items per month. It costs $150 per order of the items, and it costs $2 per item per year to keep in stock. The lead time to receive a new order for the staff is 10 days. The store wants a reorder point and safety stock for a service level of 95%.sh

Question 1: The optimal order size:

Question 2: The reorder point:

Question 3: The safety stock: