A 3 ounce serving of tuna provides 21 grams of protein. Use equivalent ratios to find how many grams of protein are in 9 ounces of tuna

There would be 63 grams of protein in 9 ounces of tuna.

Step-by-step explanation:

Equivalent ratios compare two different quantities the have the same rate regardless of the amount. In this example, for every 3 ounces of tuna, there are 21 grams of protein. We can write this as a ratio of: 3/21. Like fractions, we can simplify ratios by dividing the numerator and denominator by the same greatest common factor. In this case, we would divide both the numerator and denominator by 3: (3:3) / (21:3) = 1/7. So, our new ratio is for every ounce of tuna, we have 7 grams of protein. Using equivalent ratios, we can set up our ratios to solve for the grams of protein in 9 ounces of tuna: 1/7 = 9/x. Since we have to multiply both the numerator and denominator by the same factor, in this case 9, then our x = 63 grams of protein.