Question

Which is a graph of a proportional relationship?

Answer 1

The one on the bottom left.

Explanation:

The graph of a proportional relationship is a line that goes up at a constant rate and goes through the origin.

Since it is connected to the origin it's proportional

notice how none of the others are connected to the origin

It needs to be a straight line

So, x and y have a proportional relationship.

Answer 2

The form of the equation of a proportional relation is y = kx, where k is the constant of proportionality.

A graph of a proportional relationship is a straight line that passes through the origin.

The constant of a proportionality in a graph of a proportional relationship is the constant ratio of y to x (the slope of the line).