1. **State the problem:** We are given the equation $Y = 2.5x$ and a graph showing the relationship between cups of lemonade mix (x-axis) and cups of water (y-axis). 2. **Understand the equation:** The equation $Y = 2.5x$ means that for every 1 cup of lemonade mix, you need 2.5 cups of water. 3. **Interpret the graph:** The graph plots points where the y-value is 2.5 times the x-value. For example, if $x=1$, then $Y=2.5 \times 1 = 2.5$ cups of water. 4. **What to do:** Use the equation to find how many cups of water you need for any given amount of lemonade mix by multiplying the number of cups of mix by 2.5. 5. **Example:** If you have 4 cups of lemonade mix, then $$Y = 2.5 \times 4 = 10$$ So, you need 10 cups of water. This is a direct proportional relationship where water needed increases linearly with lemonade mix.