In Table 12 are presented the Subject Ratios in the same order as the Quotients appear in Table 1.[15] There plainly is a rapid rise of SQ⁄IQ from period to period, excluding all pupils who did not take all tests and excluding Grade III; which includes all children taking all tests who were in school in June, 1920, and were Grade IV and above in November, 1918. The average AccR is 98.24 in November, 1918, and 102.78 in June, 1920. The average IQ for these children is 105.22. The S.D_{AccR₁₉₁₈} is 11.17; the S.D._{AccR₁₉₂₀} is 9.09; the S.D._{IQ} is 19.24. It is obvious that the average amount of product per intelligence has increased, that the range of AccR’s has decreased (which means that factors causing disparities, other than intelligence, have been removed), and that the S.D. of the AccR’s is about one half the S.D. of the IQ’s. M’s are about equal so it is not necessary to use coefficients of variability. The variability of children, intelligence aside, is only one half what the variability is otherwise. The correlations when IQ = _X_, AccR₁₉₁₈ = _Y_ and AccR₁₉₂₀ = _S_ and when AccR = average of Vocabulary, Reading and Completion Ratios, are:[16] _r__{X.Y.} = -.602 _r__{X.S.} = -.493 _r__{Y.S.} = +.549 The remaining disparity is then due to something which is in negative correlation with intelligence. The number of cases here is only 48. The P.E.’s are then as follows: P.E._{M} P.E._{S.D.} _X_ 1.91 1.35 _Y_ 1.11 0.79 _S_ 0.90 0.64 P.E._r__{X.Y.} = .06 P.E._r__{X.S.} = .08 P.E._r__{Y.S.} = .07 The differences between the M’s and between the S.D.’s of our 1918 and our 1920 AccQ’s; namely, 102.78 - 98.24 = 4.54 and 11.17 - 9.09 = 2.08, have formed a step in the argument. We must have the P.E.’s of these amounts in order to establish the reliability of the quantitative indices we employ: P.E._{diff} = √P.E._{X}² + P.E._{Y}² - 2 _r__{XY} P.E._{X} P.E._{Y} P.E._{M₂₀-M₁₈} = 0.94 P.E._{S.D.₁₈-S.D.₂₀} = 0.47 These differences are then reliable. If the same data were accumulated again in the same way with only 48 cases, the chances are even that the 4.54 would be between 3.50 and 5.48 and the 2.08 between 1.61 and 2.55. That there would be positive differences is practically certain, since the difference between the means is over four times as large as its P.E., and the difference between the S.D.’s over four times as large as its P.E.