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:
In other words, 68% of the norm group has a score within one standard deviation of the average (100). Also, 95% of the norm group has an IQ score within two standard deviations of the average. So, 95% of the norm group has a score between 70 (100 â 30) and 130 (100 + 30).