Answer:
5/4
Explanation:
Given the equation y = 5/4x this relationship is an inverse proportionality i.e the y variable is inversely proportional to x.
Mathematically y = k/x where k is the proportionality constant.
Comparing y = 5/4x with y = k/x, the constant of proportionality k in he function y = 5/4x is 5/4