During a falling-head permeability test, the head fell from 49 to 28 cm in 4.7 min. The specimen was 8 cm in diameter and had a length of 85 mm. The area of the standpipe was 0.45 cm^2. Compute the coefficient of permeability of the soil in cm/s, m/s, and ft/d. What was the probable classification of the soil tested?