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Answer:
Second choice: 4.
Step-by-step explanation:
The constant of proportionality is also the slope, or rate of change. The slope formula can be used to solve this problem:
[tex]m = \frac{\text{rise}}{\text{run}} = \frac{y_2 - y_1}{x_2 - x_1}[/tex]
Plug in points from the graph into the equation.
[tex]m = \frac{4 - 0}{1 - 0}[/tex]
m = 4.
Therefore, the constant of proportionality is 4.
