Statistics is the mathematics of the collection, organization, and interpretation of numerical data, especially the analysis of population characteristics by inference from sampling. The most familiar statistical measure is the arithmetic mean, which is an average value for a group of numerical observations.
A second important statistic or statistical measure is the standard deviation, which is a measure of how much the individual observations are scattered about the mean. This section contains the most frequently used formulas, rules, and definitions regarding to the following:
Sets
Permutations and Combinations
Probability
Distribution
Reliability
A set is a collection of object called elements. In mathematics we write a set by putting its elements between the curly brackets {}.
Set A which containing numbers 3, 4, and 5 is written
Empty set
A set with no elements is called an empty set and is denoted by
Subset
Sometimes every element of one set also belongs to another set:
A set A is a subset of a set B because every element of set A is also an element of set B, and it is written as
Set equality
The sets A and B are equal if and only if they have exactly the same elements, and the equality is written as
Set union
The union of a set A and set B is the set of all elements that belong to either A or B or both, and is written...
TABLE OF CONTENTS 
