Final answer:
To adjust the proportions of ingredients in a recipe, set up a proportion using the original recipe and the desired amount of one ingredient. Cross-multiply and divide to find the amount of the other ingredients needed to keep the ratios the same.
Step-by-step explanation:
When you want to adjust the proportions of ingredients in a recipe while keeping the ratios the same, you need to set up a proportion using the original recipe and the desired amount of one ingredient. In the given scenario, if 2 cups of tomato sauce are used instead of 6 cups, you can set up the proportion: 1 tsp of mustard seeds : 2 cups of tomato sauce = 1 tsp of mustard seeds : x. You can solve for x by cross-multiplying and dividing to find that x is equal to 4/3 tsp of mustard seeds. Similarly, if 2 tablespoons of scallions are used instead of 4 and one-half tablespoons, you can set up the proportion: 1 tsp of mustard seeds : 4 and one-half tablespoons of scallions = 1 tsp of mustard seeds : x tablespoons of scallions. Cross-multiplying and dividing will give you x = 3 tablespoons of scallions.