<span>Z $ xy then Z = Kxy. When x = 2 and y = 3, and Z = 60, our constant of variation becomes
60 = K * 2 * 3
K = 10. Our constant of proportionality equals 10. We would need that in the second part of the equation.
When x = 4 and y = 9, we have
Z = 10 * 4 * 9 = 360</span>