Answer:
18
Explanation:
w varies directly with z, let k be the constant of proportionality, hence this can be represented by the equation:
w = kz
When z = 4, w = 12, hence we need to find the value of the constant of proportionality, substituting:
12 = 4k
Dividing both sides by 4:
12/4 = 4k/4
k = 3
Therefore the equation becomes:
w = 3z
The value of w when z = 6 is given as:
w = 3(6)
w = 18