There is a considerable body of literature on the graphic method. A good comprehensive development of principles appears in several chapters of EzekielMordecai, Methods of Correlation Analysis (2d ed.; New York: Wiley & Sons, 1956), and more briefly in EzekielMordecaiFoxKarl, Methods of Correlation and Regression Analysis (3d ed.; New York: Wiley, 1959). The most extensive applications to business analysis, as far as I know, are to be found in SpencerMilton H.ClarkColinHoguetPeter, Business and Economic Forecasting (Homewood, Ill.: Richard D. Irwin, Inc., 1961).
2.
See, for example, the superb recent book by FerberRobertVerdoornP. J., Research Methods in Economics and Business (New York: Macmillan, 1962), p. 94. Many other works could be cited, especially in various fields of agricultural economics where graphic techniques have received wide application by statisticians and econometricians.
3.
It has been shown many times how each of these net relationships may approximate a least squares line and hence yield a maximum likelihood fit. See, for instance, RoosC. F., “A General Method of Fitting Lines and Planes Where All Variates Are Subject to Error,”Metron (Rome, Vol. XIII, 1937), pp. 3 ff.
4.
SeeFooteR. J.IvesJ. R., Statistics and Agriculture, I, 13–18.
