A 30 ft tall, 1.5:1 slope is to be built as shown in Figure 14.20. The soil is homogeneous, with c^{\prime }= 400 lb/ft^{2} and Φ^{\prime } = 29°. The unit weight is 119 lb/ft^{3} above the groundwater table, and 123 lb/ft^{3} below. Using the ordinary method of slices and an effective stress analysis, compute the factor of safety along the trial circle shown in Figure 14.22.