The first column is the ratio you start with. The next column in the table should be the reduced fraction. To properly reduce a fraction, you divide the same number on the top and bottom of the fraction. Melody instead subtracted 1 in the top and bottom of the fraction to reduce it. She should have divided the top and bottom by 2 to get the second column of 1 pound of turkey and 3 people served. The final column is designed to be the answer to the initial question of how many people are fed by 15 pounds of ground turkey. Starting with column 2 (the reduced ratio of 1/3), multiply the top by 15 to get 15 pounds of ground turkey. Then do the same to the bottom of the fraction. 3 x 15 = 45 people fed. So the table should have been Pounds of turkey 2 1 15 People served 1 3 45 Melody's overriding error was in believing that adding or subtracting numbers to both the top and bottom of a ratio/fraction keep its value the same. Instead, only multiplying or dividing the top and bottom by the same number creates an equivalent fraction.
Using a graphing calculator to solve equations such as these is quick and easy. It is one of my favorite methods. The attached graph shows the solution is ...
