Proyective Method
Rule of Three
Measures of Dispersion
Normal Distribution


The Statistic is not another thing that the mensurabilidad of the random facts, is to deal with to systematize what in fact it is not a system, is to create a number which he is not arithmetic, is to look for what could be from which it is.

Proyective Method

The traditional method for the learning of basic elements of statistics consists mainly of three phrases:

1. - Memorization of the definition of the concept.

2. - Identification of the concept with a formula.

3. - Substitution of formula data.

Everything works well until problems with the identification arise from some data of the problem.

Also problems arise when the elementary concepts begin to be related between if to arrive at the advanced concepts but, the problems of this type arise (generally in 2° course) by an ignorance from "why" of the formulas.

In the projective method part of the concept, and with the aid of the rule of three reaches the same result that throw the formulas, with the difference of which the result is obtained by a common sense, obtaining an identification, not of the data with some symbol of the formula, but of the data with the problem to solve.

It is common in statistic books to start off of the base of which the student already dominates the fundamental elements of the mathematics, we we go from the opposite assumption.