âº EVC System. A disabled refuge is a relatively safe area within a building or exit staircase for mobility impaired occupants, allowing building management and emergency services to safely assist these people from the building.
Standard deviation is a number used to tell how measurements for a group are spread out from the average (mean), or expected value. A low standard deviation means that most of the numbers are very close to the average. A high standard deviation means that the numbers are spread out.
The standard deviation of a random variable, statistical population, data set, or probability distribution is the square root of its variance. It is algebraically simpler, though in practice less robust, than the average absolute deviation.his means that most men (about 68%, assuming a normal distribution) have a height within 3 inches of the mean (67â73 inches) â one standard deviation â and almost all men (about 95%) have a height within 6 inches of the mean (64â76 inches) â two standard deviations.