Aiko Hamaguchi is the manager of a small sushi restaurant called Little Ginza in Phoenix, Arizona. of her job Akiko has to purchase salmon every day for the restaurant. For the sake of freshness, it is important that she the right amount of salmon daily. Buying too much may result in wastage and buying too little may disappoint some customers on high-demand days. Akiko has estimated that the daily consumption of salmon is normally distributed with a mean of 12 and a standard deviation of 3.2 pounds. She has always bought 20 pounds of salmon every day. Lately, she has been criticized by the owners because this amount of salmon was too often resulting in wastage. As part of cost cutting, Akiko is considering a new strategy. She will buy salmon that is sufficient to meet the daily demand of customers on 90% of the days.

Akiko wants to use the above information to:

1. Calculate the proportion of days that demand for salmon at Little Ginza was above her earlier purchase of 20 pounds.

2. calculate the proportion of days that demand for salmon at Little Ginza was below 15 pounds. 

3. Determine the amount of salmon that should be bought daily so that it meets demand on 90% of the days.