To find the constant of proportionality in the given plotted points, we can use the formula for direct variation, which is typically represented as \( y = kx \), where \( k \) is the constant of proportionality.
From the points provided:
- (0, 0)
- (2, 14)
- (4, 28)
- (6, 42)
- (8, 56)
- (10, 70)
- (12, 84)
We can calculate \( k \) by choosing one of the non-zero points, for example, (2, 14).
Using the point (2, 14): \[ y = kx \implies 14 = k(2) \] Solving for \( k \): \[ k = \frac{14}{2} = 7 \]
To ensure consistency, let's verify the value of \( k \) with a couple more points.
For the point (4, 28): \[ y = kx \implies 28 = k(4) \] \[ k = \frac{28}{4} = 7 \]
For the point (6, 42): \[ y = kx \implies 42 = k(6) \] \[ k = \frac{42}{6} = 7 \]
These checks confirm that the constant of proportionality \( k \) remains consistent across these points.
Thus, the constant of proportionality for this graph is: \[ \boxed{7} \]