1. You can do 90 sit-ups in 2 minutes. Your friend can do 135 sit-ups in 3 minutes. Do these rates form a proportion? Explain
2. The ratio of quarters to dimes in a coin collection is 5:3. You add the same number of new quarters as dimes to the collection.
a. Is the ratio of quarters to dimes still 5:3?
b. If so, illustrate with an example. If not, give a counter-example.
3. You are 13 years old, and your cousin is 19 years old. As you grow older, is your age proportional to your cousin's age? Explain your reasoning
