ABSTRACT
Correlation-a certain kind of stochastic relation between two or more random variables; it relies on such a regularity that any changes in the values of one variable are accompaniedby systematic stochastic changes in the values of the second variable or other variables. Correlation coefficient-a basic measure of the strength of the stochastic relationship between the random variables being investigated Critical region of test-a region of the rejection of the verified statistical hypothesis; the region is determined by the test that is applied. Degrees of freedom (the number)—the number of independent outcomes of the observation reduced by the number of relationships that connect these outcomes among themselves. When an estimation of the structural parameters of the regression function is done and their significance is tested, then the number of degrees of freedom equals the number of observations reduced by the number of parameters that are being estimated. Error of type I (error of the first kind)—an error that may be made during the verification of a statistical hypothesis; it relies on the rejection of the true hypothesis. Error of type II (error of the second kind)—an error that may be made during the verification of a statistical hypothesis; it relies on the approval of the false hypothesis. Estimation-the process of finding an estimate; an approximate calculation; in mathematical statistics a chapter on such a statistical inference that deals with the assessment of the unknown values of parameters in the general population based on a sample taken from it.
