When many possible values of )' can be associated with any one value of X, the relationship between variables X" and ) is said to be stochastic. In regression analysis, the difference between the regression estimate of an individual Y, or Y , and the mean. Y. of all the observations of the dependent variable is the explained deviation of Y. The ratio of an estimated partial regression coefficient to its standard error, such as by / sMy , is called a p-value. A regression coefficient, divided by its standard error, is called the F ratio