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.
A related term is Variance. The variance is the standard deviation squared, and the variance is often called the mean squared error. Sample Standard Deviation Definition: The sample standard deviation is the square root of the sum of the squared differences around the arithmetic mean divided by the sample size minus 1.he variance is the standard deviation squared, and the variance is often called the mean squared error. Sample Standard Deviation Definition: The sample standard deviation is the square root of the sum of the squared differences around the arithmetic mean divided by the sample size minus 1.