Answer:
1) Constant of proportionality, k = 2
Explanations:
The given relationship for the graph is y = kx
Where k is the constant of proportionality
The constant of proportionality, in this case, can also be regarded as the rate of change of y with x
We are going to pick the coordinates of any two points on the line and find the slope (constant of proportionality)
Let us pick the points (1, 2) and (2, 4)
[tex]k\text{ = }\frac{4-2}{2-1}[/tex]
k = 2 / 1
k = 2
