If x and y are positive numbers and z = xy^2, a 50 percent increase in x and a 10 percent decrease in y would result in which of the following changes in z?
Choose the correct answer: A) decrease of 4.5% B) decrease of 14.5% C) increase of 4.5% D) increase of 21.5% E) increase of 35.5%
After the changes, z = 1.5x*(0.9y)^2 = (1.5*0.81)xy^2 = 1.215*z   The answer is increase of 21.5%.
<result>D</result>
If x and y are positive numbers and z = xy^2, a 50 percent increase in x and a 10 percent decrease in y would result in which of the following changes in z?