Answer:
2
Step-by-step explanation:
If we look at the y-value of positive 2 [2 on the x-axis], we see that it is 4.
The proportion of 2 to 4 is 2
You might even think of it as for every 'point' you score along the x-axis, you move forward 2 spaces on the y-axis. This may be called the constant of proportionality, or what is also commonly referred to as the "slope" of the graph.
(I am not aware of the level of math you are at*, but in y = mx + b, the "m" is the slope. This can specifically be found by the change in y [or the rise] over the change in x [or the run] between two points. <em>For this graph, that means the m would be 2, y = 2x + b . Because this line is not shifted up/down left/right any units, we know that b = 0. So, the equation for this line is y = 2x [or f(x) = 2x]</em>)
<u>*if this paragraph feels unfamiliar that is okay</u>
If you want to, you can check another point, such as 3, which we see lines up with 6. 3 to 6 is a proportion of 2 [6 / 3 = 2]
[If we want to use the slope formula [change in y / change in x], we can check we are correct with the two points we have found]
[(3 , 6) can be our 1st point, and (2 , 4) can be our 2nd point]
[ <u>1st y - 2nd y</u> <u>6 - 4</u>
1st x - 2nd x] 3 - 2

So, the constant proportionality / the slope of this graph is 2.