Answer:
f(x) = 8
Step-by-step explanation:
We are given that
f(x)∝x
Using constant of proportionality k we can say that
f(x) = kx
where k is always constant for all values of x and f(x)
now we are given that for x = 10 , we have f(x) = 2
This will help us to determine k , once we have the value of k , we can determine the f(x) for x = 40
Hence Now we have
f(x) = 2 , x = 10
putting them into
f(x)=kx
2=10k
k=1/5
Hence we now know the value of k as 1/5
Now we find f(x) at x=40
f(x)=(1/5) x 40
f(x) = 40/5
f(x) = 8
Hence this is our answer
