Question

The variable Z is directly proportional to X. When X is 12, Z has the value 228. What is the value of Z when X = 18

Answer 1

Here, z = kx

k = z/x
k = 228/12
k = 19

So, when x = 18, 
z = 19 * 18
z = 342

In short, Your Answer would be: 342

Hope this helps!