INTEX. 411
n-fold correlation, 247-249; ex- ' occupation (partial correction for
pression of correlations and re- age-distribution), 52-53 ; in Enggressions
 in terms of those of land and Wales, 1881-1890, table,
higher order, 249-250; consist- 77; from diphtheria, table, 98,
ence of coefficients, 250-251; diagram, 97 ; infantile and genefallacies,
 251-252 ; limitations in ral, correlation of movements,
interpretation of the partial cor- 197-199 ; standardisation of, for
relation-coefficient, partial associa- age and sex-distribution, 52-53,
tion and partial correlation, 252 ; 223-225, refs., 226, 392; applicapartial
 correlation in case of nor- tions of theory of sampling—
mal distribution of frequency, deaths from accident, 265-266.
331-332. Refs., 252-253, 332-333, deaths in childbirth, 282-284,
392. deaths from explosions in mines,
Uorrelation ratio, 204-207 ; standard 287-288; inapplicability of the
error, 352; refs., 209; partial, theory of simple sampling, 260-252,
 and refs., 252, 392. 261, 282-284, 285-286, 287-288 ;
Cosin, values of estates in 1715, 100. criteria (refs.), 390.
Cost of living, refs., 390-391. Deciles, 150-152; standard error of,
Cotsworth, M. B., refs., multiplica- 337-341.
tion table, 358. Defects : in school children, associa-Cournot,
 A. A, refs., theory of prob- tion of, 12, 4546, refs., 15; cenability,
 361. sus tabulation of, 14-15.
Crawford, G. E., refs.,, proof that De Morgan, A., refs., Formal Logic,
arithmetic mean exceeds geo- 23; Theory of Probabilities, 361.
metric, 130. Detlefsen, J. A., refs., fluctuations of
Crelle, A. L., refs., multiplication sampling in Mendelian population,
table, 358. 392.
Crops and weather, correlation, 196- Deviation, mean, 134; generally,
197. 144-147 : def., 144 ; is least round
Crum, L. W., refs., Economic Statis- the median, 144-145; refs., 154;
tics, 398. calculation of, 145-146, (qu. 7)
Cunningham, E., ref., omega-func- 155-156 ; comparison of advantions,
 314. tages with standard-deviation,
Czuber, E., refs., Wahrscheinlich- 146 ; of magnitude with standardkeitsrechnung,
 361; Die statis- deviation, 146-147; of normal
tische Forschungsmethode, 397. curve, 304.
Deviation, quartile. See Quartiles.
DarBIsHIRE, A. D,, data cited from, — root-mean-square. See Devia-128,
 265. Refs., illustrations of tion, standard.
correlation, 188, 273. — standard, 134-144; def., 134;
Darwin, Charles, data cited from, relation to root-mean-square de-269-270.
 viation from any origin, 134-135 ;
Datura, association between colour is the least possible root-meanand
 prickliness of fruit, 37, 38, square deviation, 135; little
(qu. 10) 275, 380-381. affected by small errors in the
Davenport, C. B., data as to Pecten mean, 135; calculation for uncited
 from, 158. Refs., statistical grouped data, 135-137, for a
tables, 358. grouped distribution, 138-141;
Day, E. E., refs., Statistical Analysis, influence of grouping, 140, 211-398.
 212; range of six times the s.d.
Deaf-mutism, association with im- contains the bulk of the observabecility,
 33-34, 38; frequency tions, 140-142, 309; of a series
amongst offspring of deaf-mutes, compounded of others, 142-143 ;
table, 104. of N consecutive natural numbers,
Deaths, death-rates, association with 143 ; of rectangle, 143 ; of arrays

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