Determine the clear sky day and the cloudy day work-plane illuminances for a 30 ft long, 30 ft wide, 10 ft high light-colored room. A 20 ft long by 7 ft high window with ¼-in clear glass faces 10°E of south, the building is at 32°N latitude, and it is January 15 at 2 p.m. solar. The ground outside is covered by dead grass.