Hopefully I can explain this well enough..
If you've ever heard of slope, it is the same as constant of proportionality. If you haven't, it's pretty simple to find on a graph. Look where the line perfectly hits the graph numbers by at least two times. So, on the graph, you can see that it goes through (1, 4) and (2, 8). You can find the slope two ways from this point, but I'm not really sure how to explain it just from typing, so I'll explain one the way it's written.
The formula for finding slope is y2-y1/x2-x1. Plugging in the numbers in the equation, it should look like 8-4/2-1, which simplifies to 4. This is the complicated way, so I'm sorry, but if you want to do the graph way, the way it's written is rise/run.
Equations are y=mx+b. m stands for slope and b is the y-intercept. We covered the slope (4), so we just need the intercept. The intercept is just asking where the line goes through y. We can see that it started at 0, so the equation is simply y=4x.
Now onto the second question. I'm a little confused if the number of baskets is x, or if the cost is x... I'm just going to go on and guess that the Number of Baskets is x.
Finding the constant of proportionality is so much easier on this because you can do 12/3 which gets you 4. All of the others have this too, so you know it's 4. In the end, the equation is, once again, y=4x.
So, in the end, these should and hopefully be the correct answers:
3.
Constant of Proportionality: 4
Equation: y=4x
4.
Constant of Proportionality: 4
Equation: y=4x
