A laboratory consolidation test was performed on a clayey soil specimen, which was drained on both top and bottom. The time for 50% consolidation was 6.2 minutes, and the specimen's thickness at 50% consolidation was 0.740 in. Two points on the field consolidation line have coordinates (p1, e1) and (p2, e2) of (1000 psf, 1.167) and (2000 psf, 1.108), respectively. Find the coefficient of permeability of the clay for the given loading range.