Answer:
Graph 1. y = 5kx
Graph 2. y = 9kx
Graph 3. y = 2kx
Graph 4. y = 3kx
Explanation:
To find the constant proportionality of each graph, first you need to search for any dot on the straight line. Then, the number on the Y and X axis of that dot, divide both of them. For example, in graph #1 on the second dot, the numbers are 80 and 16. The quotient of that is 5. The quotient of those other numbers in that graph are also 5. The instructions ask to use the formula "y = kx". Therefore, y = 5kx.