# Math Help - Variation

1. ## Variation

Suppose varies directly as the cube of . If when , what is if is 10?

Please help me I'm stuck on this and I have an online based test that is due pretty soon.

2. Originally Posted by grud315
Suppose varies directly as the cube of . If when , what is if is 10?

Please help me I'm stuck on this and I have an online based test that is due pretty soon.
Hi grud315,

If p varies directly as the cube of q, then we have:

$p=kq^3$

Substitute your values p = 7 and q = 11 and solve for k.

$7=k(11)^3$

k is your constant of variation.

Use this value of k, along with q = 10 to solve for p.

$p=k(10)^3$

3. Got it, p = 5.259203606.

Thanks a million.