30. Trevor’s recipe calls for 3 cups of flour and 2 cups of sugar. He is making a larger batch and using 9 cups of flour and 4 cups of sugar.
    Use cross products to tell whether the and are in proportion. Show your work.

To determine if the ratios and are in proportion, we can use cross products. We will set up the equation:

Calculating both sides:

Since , the two ratios and are not in proportion.

Now that we’ve established that, let’s think about the historical use of ratios and proportions in cooking. In ancient civilizations, such as Egypt and Mesopotamia, bakers developed standardized measurements to ensure their bread recipes turned out consistently. This practice of precise ratios laid the groundwork for modern cooking and baking recipes that rely on accurate ingredient measurements.

For a real-world application, think of ratios like that of a recipe being used in a catering business. If you’re doubles or triples your batch for a party, keeping those ratios consistent ensures your dish tastes the same no matter the size. Always use those cross products when scaling recipes up or down to avoid cooking disasters!