Find a rational number halfway between 3/8 and 4/9

Jackie purchased 3 bottles of water and 2 cups of coffee for the family for $7.35. ryan bought 4 bottles of water and 1 cup of coffee for his family for 7.15. how much does each bottle of water cost? how much does each cup of coffee cost?

Find the difference (8ab+a+2) - (3ab+6)

Create a data set with 8 points in it that has a mean of approximately 10 and a standard deviation of approximately 1.