The equation of the line is ?

This relationship is Linear , but not proportional.
To make this relationship proportional, we would shift the graph Up 2
y = 2/3 x - 4
y = 3/2 x
y = -4x + 2
y = -4x + 2/3

It is not possible to determine the equation of the line without more information.

The slope of the graph is 2

The y-intercept of the graph is (0, 2)
The equation of the graph in slope-intercept form is y = 1/2 x + 2
This is a ? relationship.

This is a linear relationship.

The constant of proportionality is 1/5

Write an equation that represents this graph. y = 1/5 x
This is a proportional relationship because the y-intercept is ?

The y-intercept of the equation y = 1/5x is 0. Therefore, this is a proportional relationship.