## Identify Proportional Relationships

## Formative Assessment

# Summary of the Math: Identify Proportional Relationships

**Read and Discuss**

- Being able to identify proportional relationships is important in mathematics.
- There are three ways that you can tell whether the relationship between two varying quantities is proportional:
- If the graph of the relationship between the quantities is a line that passes through the point (0, 0), then the relationship between the quantities is proportional.
- If you can express one quantity in terms of the other by using a formula of the form
*y*=*kx*, then the relationship between the quantities is proportional. - If the ratios between the varying quantities is constant, then the relationship between the quantities is proportional.

- Remember that even if the graph of the relationship between two varying quantities is a line, the relationship is only proportional if the line passes through the point (0, 0).

Note: Sometimes proportional relationships are said to be *directly proportional*.

## Hint:

Can you:

- Describe three ways that you can tell whether a relationship between two varying quantities is proportional?