Linear Regression

Generally, in two mutually related statistical series, the regression analysis based on graphic method. Under graphic method the values  of X and Y variable  are plotted  on a graph  paper in the form of a scatter Diagram .When  two lines are drawn passing nearest to the dots, these are known as regression line. If these lines are straight, the regression is called   as linear. The equations of these straight regression lines are called equations of the first degree. Regression equation of y on x : y =a+bX and regression equation of X and y:x =a+by. If these regression lines take the form of smooth curve, the regression will be called as curvilinear.