Suppose you are given that z = c y2/x3 where c is some number. For a particular value of c, x and y, z is equal to 129. Suppose x is decreased by a factor of 2.3 and y is decreased by a factor 7.9. What is the new value of z?

Z = 129 * (2.3)^3 * (1/7.9)^2 = 25.1