2 THEORY OF STATISTICS.
effect of removing conditions of Small chances, law of, 265-266, 366
simple sampling on standard error 370; refs., 273, 393.
of mean, 347-350 ; standard error. Snow, E. C., refs., estimates of popuof
 standard-deviation and co- lation, 130, 253 ; lines and planes
efficient of variation, 351 ; of co- of closest fit, 209.
efficients of correlation and re- Soil surveys, errors in, refs., 396.
gression, 352 ; of correlation-ratio Soper, H. E., frequency arrays, ref.,
and test for linearity of regression, 393:
352 ; refs., 354-356, 395. — refs., probable error of correlation-Saunders,
 Miss E. R., data cited coefficient, 355, 395; of biserial
from, 37. expression for correlation - co-Scale-reading,
 bias in, 362-363. efficient, 355; tables of exponen-Scheibner,
 W., difference between tial binomial limit, 273.
arithmetic and geometric, arith- Southey, Robert, cited re Cosin’s
metic and harmonic means, (qu. 8 Names of the Roman Catholics,
and qu. 9) 156. etc., 100.
Scripture, E. W., use of word Spearman, C., effect of errors of
“statistics,” 3. observation on the standard-de-Secrist,
 H., refs., Introduction to viation and coefficient of correla-Statistical
 Methods, 398. tion, 213-214. Refs., effect of
Semi-interquartile range. See Quar- errors of observation, 225, 333,
tiles. 391 ; rank method of correlation,
Sex-ratio of births : correlation with 335
total births, 163, 175, 207; dia-  Splawa-Neyman, J., refs., probable
gram, 176; constants, (qu. 3) 189; errors, 395.
application of the theory of sam- Spurious correlation of indices, 215-pling
 to, 262-264, (qu. 7) 275, (qu. 216 ; refs., 226, 392.
1, 2) 289, refs., 273; standard Standard-deviation. See Deviation,
error of ratio of male to female standard.
births, (qu. 11) 275. Standardisation of death-rates, 223
Shakespeare, W., use of word 225 ; refs., 226, 392.
statist,” 1. Statist, occurrence of the word in
Sheppard, W. F., correction of the Shakespeare and in Milton, 1.
standard-deviation for grouping, Statistical, introduction and de-212,
 307 ; theorem on correlation velopment. .in the meaning of the
of a normal distribution grouped word, 1-5 ; S. Account of Scotland,
round medians, (qu. 4) 334; 2; Royal S. Society, 3 ; methods,
normal curve tables, 337; stan- purport of, 3-5; def., 5.
dard errors of percentiles, 344. Statistics, introduction and develop-Refs.,
 calculation and correction ment in meaning of word, 1-5;
of moments, 225; normal curve def., 5; theory of, def., 5.
and correlation, theory of sam-  Statures of males in U.K., tables, 88,
pling, 314, 333, 355; tables of 90; diagrams, 89, 91; calculanormal
 function and its integral, tion of mean, 112; means and
359. medians, 117, (qu. 1) 131; stan-Significant
 differences, 266. dard-deviation, 141 ; percentiles,
Sinclair, Sir John, use of words 153 ; standard-deviation, “mean
“ statistics,” ¢ statistical,” 2. deviation, and quartiles, (qu. 1)
Skew or asymmetrical frequency- 155 ; distribution fitted to normal
distributions, 90-102. See also curve, 305-306, 307-308; dia-Frequency-distributions.
 gram, 306; standard errors of
Skewness of frequency-distributions, mean and median, of first to
107 ; measures of, 149-150. ninth deciles, 341, 343, 344-345 ;
Slutsky, E., refs., fit of regression of standard-deviation and semilines,
 209, 391. interquartile range, (qu. 5) 355.

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