Answer & Step-by-step explanation:
To find if they have a constant of proportionality of 12, use the following:

Divide y by the x value (x,y), and if the remaining equation is true, then that table has a constant of proportionality of 12.*
:Done
*Make sure you check all the values in a table. Sometimes only the first values will have k=12, while the others don't.
**The constant of proportionality is represented by <em>k</em>.
This would be easier for you if you put it in a graph
Answer:
y-intercept = 3
Step-by-step explanation:
value that's on the y - axis