Sweet cider is delivered weekly to Cindy’s Cider Bar. Demand varies normaly with the mean of 400 liters and standard deviation of 50 liters per week. Cindy pays 20 cents per liter for the cider and charges 80 cents per liter for it. Unsold cider has no salvage value and cannot be carried over into the next week due to spoilage. Find the optimal stocking level and its stockout risk for that quantity.