Respuesta :
The constant of the variation which is the constant of proportionality is 3.
What is variation?
Variation is defined by any change in some quantity due to change in another.
b ∝ cd / f
Therefore,
b = kcd / f
where
k = constant of proportionality
Hence,
c = 4
d = 9
f = 6
b = 18
Therefore,
bf = kcd
k = bf / cd
k = 18 × 6 / 4 × 9
k = 108 / 36
k = 3
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