Answer:
9
Step-by-step explanation:
1. The formula to find constant of proportionality is k = y/x, where y = y-coordinate and x = x-coordinate.
2. Let's take the coordinate (1,9) and plug their values into that formula to get the constant of proportionality.
- [tex]k = \frac{(9)}{(1)}[/tex]
- [tex]k = 9[/tex]
Therefore, the constant of proportionality is 9.
