Fn key. Not to be confused with Function key. The Fn key, short form for function, is a modifier key on many keyboards, especially on laptops, used in a compact layout to combine keys which are usually kept separate. It is typically found on laptops due to their keyboard size restrictions.
For a finite set of numbers, the standard deviation is found by taking the square root of the average of the squared deviations of the values from their average value. For example, the marks of a class of eight students (that is, a population) are the following eight values:
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.