The variational series is presented by a certain sequence of options (x (1), …, x (n)) which are located as it should be decrease or nondecreases. X (1) call the first element of a variational series minimum: it is designated by xmin. The last element of this row is called maximum and xmax is designated. On the basis of data of a variational series the schedule is under construction.

## It is required to you

- - ruler;
- - initial information;
- - notebook;
- - simple pencil;
- - handle.

## Instruction

1. Pay attention that there are several types of a variational series: discrete and interval. Each of them has the features of construction. That variation which separate values differ at a certain size is considered a discrete variation of sign. Continuous the variation is considered in case its separate values differ among themselves at any size. In an interval variational series signsof belong not to separate value, and to the whole interval.

2. Before starting creation of an interval variational series correctly pick up the principle on which ranging of separate elements of an interval row is based. The choice of that or other sign entirely depends on uniformity of the analyzed indicators. For example, if the presented set of indicators uniform, then for creation of such variational series use the principle of equal intervals.

3. However before defining, indicators are uniform or not, make the informative analysis. The uniformity is defined by creation of the line chart and the subsequent its analysis for the purpose of identification abnormal (atypical for this variational series) observations. Besides, the principle of equal intervals is used at creation of a variational series with considerable jumps which cause is unknown.

4. Correctly determine the interval size necessary for creation of an interval variational series: it has to be such that, first, the analyzed variational series did not seem too bulky, and, secondly, the studied features were accurately traced. If intervals equal, then the size of an interval is calculated by a formula: h=R/k in which R is a scope of a variation and indicates k number of intervals. At this R is defined as the difference between xmax and xmin.

5. If creation of a discrete variational series is carried out, then you can attribute to its options not frequencies of emergence of some phenomenon, but a share of each option in the general analyzed set of indicators. These shares calculated as the relation of certain frequencies to the general indicator are called chastost and designate qi. In turn, chastost can be expressed as as a percentage, and relative numbers.