# 8th Grade Unit 3, Lesson 1 Vocabulary

## 10 terms

### Proportional Relationship

A relationship between two variables in which one is a constant multiple of the other.

### Scale Factor

A ratio between two sets of measurements; in scale drawings-the ratio of the measurement on the drawing compared to the measurement of the original subject.

### Constant Rate of Change

When the variables are multiplied by the same number; a rate that does not change.

### Variable

A quantity that can change or vary, taking on different values; a letter or symbol representing a varying quantity.

### Ratio

A comparison of two or more quantities; may be written as 3:4 or as a fraction.

### Proportion

An equation stating that two ratios are equivalent.

### Rate

A ratio that compares quantities of two different types or a relationship between two units of measurement.

### Unit Rate

A ratio that compares quantities of two different types and the quantity of the second number is "1"; a rate that has a denominator of "1" unit.

### Constant of Proportionality

The constant value of the ratio of two proportional quantities "x" and "y"; usually written y=kx, where "k" is the factor of proportionality.

### Equivalent

Having the same amount or value; similar, commensurate, equal to.