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In many studies the variable that is of interest to us is the time that would lapse before an event takes place. This event can be death or death from some particular disease; that is why analises of such data are called survival analises.An example of such a study can be a clinic examination of a new kind of therapy with malign tumors whose prognosis is unfavorable. In such an examination the final occurrence is death or remission. The study may comprise the examined who were yet to experience the final occurrence at the time when the analysis was conducted. Though the time till the final event with these patients is unknown, there are some pieces of information regarding its value; one of them is that this time must be longer than the survival time so far. The value that we have available at the moment of the analysis is called the censured value. The analysis methods must be such as to be able to use such censured values. Very often many other variables obtained at the beginning of the ex-animation and survival are mutually connected so that these variables can be regarded as prognostic. The analysis methods must be such that they can perform calculations on the basis of the prognostic variables' distribution in the sample under examination.Another example of the studies in which the survival analyses are used is the study of the specific professional mortality in which it is examined if the group of workers exposed to the polluter exibits a higher mortality rate in comparison with the mortality of the population it is a part of. The subjects enter the study as healthy unlike clinic examination in which the subjects at the begining of the examination already suffer from some disease.Many of the methods used in the survival analyses are based upon the life tables described in the paper.