A large embankment is to be built on the surface of a 15-ft clay layer. Before the embankment is built, the initial σ'v at the middle of the clay layer is 480 psf. The results from a 1-D consolidation test on the clay from the middle of the layer are as follows: σ'p = 1800 psf, C rε = 0.0352, C cε = 0.180. If the final σ'v at the middle of the layer after the embankment loading is 2100 psf, what is the settlement, in inches, of the clay layer resulting from this loading?