Answer
In a finite well, the energy is less than it would be if the potential well were infinite.
Work Step by Step
In a finite well, the matter wave leaks into the walls of the well. However, in an infinite well, the matter wave is restricted by the walls of the well.
Therefore, in a finite well, the de Broglie wavelength is greater than it would be if the potential well were infinite.
We can write an expression for the energy:
$\lambda = \frac{h}{\sqrt{2mE}}$
$\lambda^2 = \frac{h^2}{2mE}$
$E = \frac{h^2}{2m~\lambda^2}$
Since $\lambda$ is greater in a finite well, then the energy $E$ is less in a finite well.
In a finite well, the energy is less than it would be if the potential well were infinite.
