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. The standard deviation is a measure of the variability of the distribution of a random variable. To estimate the standard deviation. calculate the weighted sum of the squares of the differences of the observations in a simple random sample from the sample mean.