Zvaries jointly with x and y.

when x = 2 and y = 3, z = 60.

what is the value of z when x = 4 and y = 9?

First, let's find "k" the constant of variation:

z= k.x.y (since z varies jointly with x and y)

60 =k.(2).(3) → 60 = 6k and k =10, So z = 10x.y

z= 10(4)(9) = 10(36) and z = 360

Where is the problem

2160ft^3 i think you could use a formala to you out with this in the future