This is a case in which it may be said that the figures are worthless without the signature.
CHAPTER VIII
STATISTICAL METHODOLOGY
Having taken measurements with the rigorous technical precision that is to-day demanded by anthropometry, we should know how to extract from these figures certain laws, or at least certain statistical conclusions.
There are two principal methods of regrouping the figures:—mean averages and seriations.
Mean Averages.—Averages are obtained, as is a matter of common knowledge and practice, by taking the sum of all the figures and dividing the result by the number of data. The general formula is as follows:
(a+b+c+d)/(1+1+1+1)
When comparative figures are given, as, for example, those recorded by Quetélét for the stature, the diameters of the head, etc., such figures are always mean averages.
Such averages may be more or less general. We might, for example, obtain a mean average of the stature of Italians, and this would be more general than the mean stature for a single region of Italy, and this again more general than the mean stature for a city, or for some specified social class, etc.