Freshly made yogurt is stocked at a nearby grocery store each week. At the end of the week unsold yogurts is reduced in price by 75% and always sells for this lower price instantly. If weekly demand for yogurt is normally distributed with a mean of 220 units and standard deviation of 25 units, find the price for which a fresh unit of yogurt sells. Assume a service level of 98% and that the store purchases yogurt for $ 0.75.