Explore Proportional and Linear Relationships

A proportional relationship is a relationship between two quantities where the ratio of one quantity to the other is constant.

A graph starts at the origin (0,0) when the value of both variables is zero at that point.

A graph is proportional if it is a straight line that passes through the origin.

A linear relationship is a relationship that can be represented by a straight line on a graph.

The slope of a line is a measure of its steepness, calculated as the rise over the run between two points on the line.

The y-intercept is the point where a line crosses the y-axis, indicating the value of y when x is zero.

If a graph is not proportional, it means that the ratio between the two quantities is not constant.

An example of a proportional relationship is the relationship between distance and time when traveling at a constant speed.

The equation of a proportional relationship can be written as y = kx, where k is the constant of proportionality.

The constant of proportionality can be found by dividing the value of y by the value of x for any point on the line.