If X, Y, Z and W are in fourth proportion. X = 3, Y = 13 and W = 39, determine Z
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. 9
Given that
If X, Y, Z and W are in fourth proportion.
first * fourth proportion = third * second proportion
X * W = Y *Z
Z = 3 * 39/13 = 9