Exercise 7 . 2 . Granite State Airlines serves the route between New York and Portsmouth , NH , with a single - flight- daily 100 - seat aircraft . The one - way for discount tickets is $100 , and the on - way fare for full-fare tickets is $ 150 . Discount tickets can be booked up until one week in advance , and all discount passengers book before all full-fare passengers . Over a long history of observation , the airline estimates that full- fare demand is normally distributed , with a mean of 56 passengers and a standard deviation of 23 , while discount-fare demand is normally distributed , with a mean of 88 passengers and a standard deviation of 14