The STD or STDEV function estimates the standard deviation of a population based on a random sample of that population as supplied by list.
The standard deviation is a measure of the dispersal of data from the mean value and is defined as the square root of the variance (see VAR).
The formula used by STD is:
SQRT(VAR(list))
STD assumes that list is a sample of the population, so use STDEVP (see STDEVP) if you wish to work with a whole population.
For example, if 5 people are chosen at random and measured for height, from a company with 40 employees, the formula:
STD(1.85, 1.9, 1.8, 1.75, 1.7)
returns 0.079 as the estimated standard deviation for the population. To get the standard deviation based on all 40 employees use STDEVP.
See also: