Answer:
y = 2.54
Explanation:
Please input an actual table, such as the following:
x y
5 12.7
6 15.24
7 17.78
8 20.32
It appears that we're converting inches to centimeters.
It so happens that 1 inch = 2.54 cm. The '2.54' is the slope of a straight line, as the number of cm equivalent to x inches is c = 2.54x.
Arbitrarily taking the 2 points (5, 12.7) and (8, 20.32), we find the slope of the line through these points. As we go from the first to the second, the x-value ('run') increases from 5 to 8 (that is, it increases by 3) and the y-value ('rise') increases from 12.7 to 20.32 (that is, it increases by 7.62. Thus, the slope of the line through these two points is m = rise / run = 7.62 / 3 = 2.54.
Now find the equation of the line thru these two points. Using the slope-intercept formula y = mx + b and the points (5, 12.7) we get this equation for the y-intercept (b):
12.7 = 2.54(5) + b
which tells us that b = 0.
Therefore, the desired relationship is y = 2.54 and this is a proportional relationship (no y-offset).