Find the constant of variation for the relationship f (x) = 40x.

A.

f (x)

B.

x

C.

20

D.

40

We are given the expression f (x) = 40x where f (x) is the dependent variable and x is the independent variable. In this case, we can see that f (x) is directly proportional to x and that the constant of propotionality is 40. Answer then to this problem is D. 40

Constant of variation is 40