V varies jointly (directly) as A and H. If V=4 when A=6 and H=2, calculate
the value of V when A=9 and H=4.
We need to find the proportionality constant, k.
So we have
V = kAH
4 = k(6)(2)
4 = k(12)
4/12 = k = 1/3
So, when A = 9 and H = 4, we have
V = (1/3)(9)(4)
V = (1/3)(36)
V = 12
