Check the ratio of the difference of y's to the difference of x's
as follows:
11-7 / 5-4 = 4 / 1 = 4
7-5 / 4-3 = 2/1 = 2
5-4 / 3-2 = 1 / 1= 1
"Proportional
Relationship": means the difference in y-coordinate over the
difference in x-coordinate is constant and does not change through all the
points!
SO it is obviously NOT a linear relation
