A supermarket sells a specific mobile brand and earns a revenue of AED $510$ per mobile. An unsold mobile incurs a holding cost of AED$40$ at the end of the month. Holding cost is a portion of the rent, insurance, and others. If there is any shortage, the market assigns a goodwill cost of AED$50$ a mobile. The store has a stocking policy of $195$ mobiles a month. The demand follows a normal distribution with a mean of $210$ and a standard deviation of $40.$