The amount of sparkling water that would be needed to mix with 9 quarts of grape juice is 18 quarts.
Ratio expresses the relationship between two or more numbers. It shows the frequency with which one value is contained in another value. According to the question, the ratio of sparkling water to grape juice is .
In order to determine the amount of sparkling water that would be needed with 9 quarts of grape juice, this equation would be used:
