Melanie is planning to make her monthly (every 30 days) travel to Antrim Crescent Place to pick up a supply of Potato chips. The trip will take Melanie about four days. Before she leaves, she calls in the order to the Marketplace. She sells Potato chips at an average rate of twelve per day (seven days per week) with a standard deviation of demand of four per day. She needs a 90 percent service probability. a. What is the service rate (or optimal fractile)? b. How many T-shirts should she produce for the upcoming event