1. **State the problem:** We have a table showing the relationship between cups of ice cream and cups of soda. We want to find how much soda Sidney will use for 19 cups of ice cream. 2. **Identify the relationship:** The table suggests a proportional relationship between ice cream and soda. We can check this by calculating the ratio of soda to ice cream for the given pairs. 3. **Calculate the ratio:** $$\frac{10.5}{3.5} = 3, \quad \frac{24}{8} = 3, \quad \frac{37.5}{12.5} = 3$$ All ratios are equal to 3, confirming the relationship is proportional. 4. **Use the formula for proportionality:** $$\text{soda} = 3 \times \text{ice cream}$$ 5. **Calculate soda for 19 cups of ice cream:** $$\text{soda} = 3 \times 19 = 57$$ 6. **Answer:** Sidney will use **57 cups** of soda for 19 cups of ice cream.