Please solve it with Excel.

ABC Company brings in sports cars and sells them in the Vietnamese market. The monthly demand for these cars follows a normal distribution, and when the company places an order, it takes one month for the cars to arrive. The average demand during this lead time is 10 units, with a standard deviation of 4 units. To maintain a service level of at least 90%, what should be the unit backorder cost? The holding cost is $5. ABC Company brings in sports cars and sells them in the Vietnamese market. The monthly demand for these cars follows a normal distribution, and when the company places an order, it takes one month for the cars to arrive. The average demand during this lead time is 10 units, with a standard deviation of 4 units. To maintain a service level of at least 90%, what should be the unit backorder cost? The holding cost is $5