Final answer:
The constant of proportionality for the relationship of cups of water to scoops of lemonade mix is 2.5 cups per scoop.
Step-by-step explanation:
The constant of proportionality can be found by setting up a proportion between the cups of water and scoops of lemonade mix. Since Mel uses 5 cups of water per 2 scoops of lemonade mix, the proportion is:
5 cups / 2 scoops = x cups / 1 scoop
To solve for x, cross multiply:
5 * 1 = 2 * x
5 = 2x
x = 2.5
Therefore, the constant of proportionality for the relationship of cups of water to scoops of lemonade mix is 2.5 cups per scoop.