A proportional relationship is a relationship between equivalent ratios.

Imagine that ice cream costs $2 per scoop.
- If you get one scoop of ice cream, you'll pay $2.
- If you get two scoops, you'll pay $4.
- If you get three scoops, you'll pay $6.

These ratios of scoops to prices are equivalent. Therefore, the relationship between the number of scoops and the total price is proportional. To find out the total price of your ice cream, you can always multiply the number of scoops you're getting by 2.