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.
Standard deviation: It is the square root of mean/average of squared deviations of data point from mean i.e. we subtract the mean from each data point; take it's square value (which is again non-negative); sum it up and divide by the number of observations. Surely, standard deviation is a better & most commonly used measure of variation. For more details on the comparison between the two, please see Mean absolute deviation vs. standard deviation 19.5k Views Â· View Upvoters