Answer:
r = 2.5
Step-by-step explanation:
The equation given says y = r * x
So, the y value would be an unknown times the given x value.
To solve for r, all you have to do is divide.
25 ÷ 10 = 2.5
12.5 ÷ 5 = 2.5
10 ÷ 4 = 2.5
2.5 is the constant of proportionality.
