we know that
If the shapes are similar
then
the ratio of the height to the diameter of the can must be equal to the ratio of the height to the diameter of the tank
so
[tex]\frac{2}{3} \frac{height\ in}{diameter\ in} =\frac{x}{6} \frac{height\ yd}{diameter\ yd}\\ \\ 3*x=6*2\\ \\x=12/3\\ \\x=4\ yd[/tex]
therefore
the answer is
The height of the tank is 4 yards
