PROPORTIONAL AND NONPROPORTIONAL RELATIONSHIPS

Building on the Essential Question

At the end of the lesson, students should be able to answer "What makes two quantities proportional?"

Objective identify proportional and nonproportional relationships

Lesson Vocabulary

proportional
nonproportional
equivalent ratios

There are several ways to determine whether or not a relationship is proportional.

• If ordered pairs of a relation show a constant ratio, it is a proportion.
• If the elements in the rows of a table for the relation have a constant ratio, it is a proportion.
• If there is a constant ratio between y- and x- coordinates of points on the graph of a relation, it is a proportion.
• If the relation can be expressed algebraically in the form y = kx, it is a proportion.

A relation that does not have these characteristics is not a proportion.