Inductive Method. 
269 
7 per cent, of the population of 1880, then running up to 13 per 
cent, in 1892. The only exceptions are two great increases of 
about 60 per cent, and 20 per cent, respectively, caused by the 
annexation of large out-lying districts to the city in 1890 and 
in 1891. 
In a similar way the population-corrections for the other col¬ 
umns are found (Table XI, p. 292). The per cents in bold 
faced type are exact, being derived immediately from the official 
census. The rest of the table is estimated. Quite evident laws 
are discovered by mere inspection of Table XII (p. 293), 
where these factors are analyzed — regularities of increase and 
decrease vertically, horizontally, and diagonally across the table 
being evident. We are thus enabled to fill in the alternate 
columns (Table XI) with tolerable assurance. 
Having this law of the increase of population, it will easily 
be seen that corresponding deductions should be made from the 
enrollments of classes through the successive grades, since the 
incoming population brings pupils that enter the different 
grades in about the same proportion as that in which the Chi¬ 
cago pupils are distributed among them. Table XIII (p. 294) 
gives the enrollment of each class as it passes through the suc¬ 
cessive grades. Table XIV ( p. 295 ) gives the true enroll¬ 
ment as corrected for increase of population. Subtracting the 
enrollment of the second grade from that of the first, gives us 
the number that dropped out of school at the first grade. 
Going through the entire table in this same way, we get Table 
XV. Number That Dropped out by End of Each Grade 
(p. 296). From these numbers taken as percentages with 
the corresponding first grade enrollment taken as abase, we get 
Table XVI. PerCent. of First Grade Enrollment Dropped out by 
End of Each Grade (p. 297). 
Although this method seems the most direct and exact, it 
will be seen that the per cents are unexpectedly large. It will 
also be seen that we have very uniform laws evident through¬ 
out these years as to the per cent, that drops out at each grade. 
The average for each period of four years makes this clear. 1 
1 Table XVII. Average Per Cent, of First Grade Enrollment 
Dropped out by End of Each Grade (Chicago), p. 298. 
