Histogram (bar chart) showing chest measurements of 5,732 Scottish soldiers, published in 1817 by Belgian mathematician Adolph Quetelet. This was the first time that a human characteristic had been shown to follow a normal distribution, as indicated by the superimposed curve.
central limit theorem
central limit theorem, in probability theory, a theorem that establishes the normal distribution as the distribution to which the mean (average) of almost any set of independent and randomly generated variables rapidly converges. The central limit theorem explains why the normal distribution arises so commonly and why it is generally an excellent approximation for the mean of a collection of data (often with as few as 10 variables). The standard version of the central limit...