Which graph shows a proportional relationship?

Question

whpalmer4 · Answer

A proportional relationship will be a straight line graph.

whpalmer4 · Answer

where the line is not vertical...

anonymous · Answer

attachment

whpalmer4 · Answer

okay, can you eliminate any candidates on the basis that the points do not lie on a straight line?

anonymous · Answer

It dose not let me

whpalmer4 · Answer

What do you mean, it does not let you?  Look at each of the 4 graphs.  Are any of them sets of points which do not fall on a straight line?  Put a ruler on your screen and check.

whpalmer4 · Answer

Well, you don't seem to be active, so I'll just describe what you need to do.

a proportional relationship will be one of the form $y = kx$ where $k$ is the constant of proportionality (or the constant of variation is another term for it)

Only one of those graphs will fit such an equation.

anonymous · Answer

wait i dont get it war do you mean

whpalmer4 · Answer

Tell me what of that you don't understand.

anonymous · Answer

all of it

whpalmer4 · Answer

Okay.  A proportional relationship (also known as direct variation) will be of the form $y = kx$ where $k$ is a constant.

Does that remind you of the equation for a line?

anonymous · Answer

oo ok ya it the 2nd one

whpalmer4 · Answer

Yes, only the second one has the points in a straight line which goes through the origin and is not vertical.

anonymous · Answer

ooo ok thanx