Answer
The area is much larger between 0 and L than it is outside the finite well.
Work Step by Step
We see from Figure 40.15a that if we square the wavefunction, the area under the curve (i.e., the probability distribution function) is much larger between 0 and L than it is outside the finite well. That makes perfect sense since the particle is confined to the well. We are much more likely to find it inside the well than outside the well.
