7th Grade Academy - Unit 4: Proportional Relationships

Percent

A ratio that compares a number to 100

Proportion ( (proportional))

An equation that states two ratios are equal

d=rt

Distance = constant speed × time Constant speed is the rate

k = y/x

The constant of proportionality is the same for the ratio of output to input for all points in a proportional relationship.

Constant of Proportionality

The 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. Y varies directly with x (y=kx is a direct variation equation)

Constant Rate of Change

The rate of change is the relationship between two quantities that are changing. is also called slope. rate of change=change in the dependent variable/change in the independent variable.

Non-Proportional

The relationship between two ratios with a rate or ratio that is not constant. When graphed the line does not pass through the origin (0,0).