Филиал Кузгту в г. Белово Кемеровское региональное отделение рэа, Россия

 
Keywords:
relative frequency polygon, population sample or sampling, qualita-
tive and quantitative, simple random selection. 
Mass random events can be represented in the form of statistical aggre-
gates of homogeneous objects. Each statistical population has different charac-
ters. Distinguish qualitative and quantitative signs. Quantitative characters can 
vary continuously or discretely. 1-for example. Consider the process of produc-
tion of a batch of batches (statistical aggregate) (mass random event). The 
standard of the part is this quality mark. Piece size is a quantitative property that 
is constantly changing. Require the study of a statistical set of homogeneous ob-
jects depending on some feature. A complete survey, i.e. a study of each of the 
statistical population objects, is rarely used in practice. If the study of the object 
is related to its destruction or requires large material costs, then it makes no 
sense to conduct a full survey. If the population includes a large number of ob-
jects, then it is almost impossible to conduct a complete survey. In such cases, a 
limited number of objects are randomly selected and inspected from the entire 
population. 
Definition. The whole population is called the whole set to be studied. 
Definition. A population sample or sampling is called a set of randomly selected 
objects. Definition.Sound population (sample or total) is the number of objects 
in a population. The total population size is determined by Nva samples n. In 
practice, they usually use that in a non-repeated sampling, the selected object is 
not returned to the general population (otherwise we take a repeat sample). 
Sample data should be sampled to estimate the total population representative 
(representative). To do this, each object must be randomly selected and all ob-
jects must have the same probability of being added to the sample. different se-

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lection methods are used. Selection methods (sampling methods) Two stages 
(population divided into groups) The only stage (general population not divided 
into groups) Simple simple (items are taken randomly from the whole set) Usu-
ally (object is selected from each default part) Combined (several from the total 
number of groups and several selected) Simple random sampling Random non-
repetitive sampling Mechanic (select one item from each group at a time) Se-
quential (From the total number of groups - rows, several are selected and they 
are fully checked) Selection methods Example 2 The plant produces 150 ma-
chines with the same product. 1. The products of all 150 machines are mixed 
and several products are selected at random - a simple random selection. 2. 
Products are placed separately from each machine. Several products are selected 
from all 150 machines, and products from obsolete and less obsolete machines 
are analyzed separately - a typical sample. One product from each of the 150 
machines is a mechanical sample. Several of the 150 machines are selected (e.g., 
15 machines) and all products of these machines are inspected - sample in series. 
Several of the 150 machines were selected, followed by several products from 
these machines - a combined sample.
The sequence of X random variables observed as a result of the study is 
called a property in statistics. Different values of the characteristic are called 
variants. A complete survey, i.e. a study of each of the statistical population ob-
jects, is rarely used in practice. If the study of the object is related to its destruc-
tion or requires large material costs, then it makes no sense to conduct a full sur-
vey. If the population includes a large number of objects, then it is almost im-
possible to conduct a complete survey. In such cases, a limited number of ob-
jects are randomly selected and inspected from the entire population.