Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. This is an OCR edition with typos. Excerpt from book: tion of the increase or decrease of time consumed will be obtained. This method can be used whenever two factors enter into the record. Groups of variables orten appear where the mere distribution of cases is important regardless of the order in which they came. These can be shown by having various ranges of values, or quantities represented along a base line and erecting above each division a column proportional to the number of cases that fall within the range of the values or quantities of that division. Such a curve will appear as a series of rectangles standing along side each other. Sometimes the distribution comes out more clearly by joining the mid-points of each of the columns. The number of groups represented on the base line and the distance by which each case is to be represented depends on the nature of the data and the purpose for which the graph is made. Tables Illustrating the Use of the Above Formulae Column (1) is the list of letters representing individuals. Column (2) is a series of measurements for the individuals. Column (3) represents the individual deviations from the average. Column (4) gives the squares for the deviations for finding S. D. The measurements are arranged in their ascending order for finding the median in column (5). TABLE 1 (1) (2) (3) (4) (5) A.273926B.2641626C.300026D.2641626E.273927F.273927G.2641627H.282427I.3663628J.2641630K.3663636L.273936M.3663636N.3663636O.366363615145015)6015)28427 Mnav. 30m.v. 4 18.93(5.D.)2 4.34 S.D.Table II presents another series of measurements for the same subjects as table I. The calculations are given in the same order. These two tables, I and II, form the basis for the calculation of the coefficient of correlation, table III. TABLE II A. 12 13 169 10 B. 11 14 196 11 C. 25 …