Final answer:
To represent the ratio of the length of Shanni's ribbon to the length of Mel's ribbon, draw a tape diagram with two lines divided into 10 equal parts, shading 7 parts for Shanni and 3 parts for Mel.
Step-by-step explanation:
To represent the ratio of the length of Shanni's ribbon to the length of Mel's ribbon, we can use a tape diagram. We will draw two lines, one for Shanni's ribbon and one for Mel's ribbon. Since the ratio is 7:3, we will divide each line into 10 equal parts and shade 7 parts for Shanna's ribbon and 3 parts for Mel's ribbon.