A grocery store carries on average 22 days of inventory of a 5lb packet of sugar. They order a truckload from the supplier every 20 days and it takes 5 days from ordering to receipt. They pay the supplier only on receipt of the goods. There is no seasonality in demand for sugar at the store, but there is random variation and demand is normally distributed. 

What is the average cycle stock, in days, held at the store?