Which of the following does not represent a direct variation?

A graph with a line running through the points two comma two and six comma six.

y equals twelve x

An x−y table shows the following coordinate pairs: six comma seven, three comma four, and zero comma zero.

Xavier took 4 pictures with his digital camera and used three point two gigabytes. He took 8 more and used another six point four gigabytes.

Question

Which of the following does not represent a direct variation?

 A graph with a line running through the points two comma two and six comma six.

 y equals twelve x

 An x−y table shows the following coordinate pairs: six comma seven, three comma four, and zero comma zero.

 Xavier took 4 pictures with his digital camera and used three point two gigabytes. He took 8 more and used another six point four gigabytes.

anonymous · Answer

All of the possible statements can be represented as a straight line plot except #3:

"An x−y table shows the following coordinate pairs: six comma seven, three comma four, and zero comma zero." 

Refer to the Mathematica attachment which shows that the three points above lie on a parabola, a curve.