Question

The variable Z is directly proportional to X. When X is 6, Z has the value 72.

What is the value of Z when X = 13?

Answer 1

z
`\alpha x`
Z=kX
where k is a constant of proportionality;
When x=6, z=72
72=6k
k=12
Z=12X
When x=13
Z=12*13
Z=156