416 THEORY OF STATISTICS.
lengths of mother- and daughter- ing of, 220-225; of binomial
frond, 185-187. series, 299; standard error of,
Lexis, W., use of term ‘ precision,” 334-350, (refs.) 355, 395.
144. Refs., Theorie der Massen-- Mean deviation. See Deviation,
erschetnungen, 273 ; Abhandlungen mean.
zur Theorie der Bevilkerungs- und. — error, 144. See Error, standard ;
Moralstatistik, 273, 361. Deviation, standard.
Linearity of regression, test for, — geometric, 108; generally, 123-205-206,
 352; refs. 391. See also 128 ; def., 123 ; calculation, 124 ;
Correlation-ratio. less than arithmetic mean, 123 ;
Lipps, G. F.. refs., measures of difference from arithmetic mean
dependence (association, correla- in terms of dispersion, (qu. 8) 156 ;
tion, contingency, etec.), 40; of series compounded of others,
Fechner’s Kollektivmasslehre, 129, 124 ; of series of ratios or pro-360.
 ducts, 124; in estimating inter-Little,
 W., data as to agricultural censal populations, 125-126 ; conlabourers’
 earnings cited from, venience for index-numbers, 126—
137. 127 ; use on ground that devia-Lloyd,
 W. E., refs., error in soil tions vary with absolute magnisurvey,
 396. tude, 127-128 ; weighting of, 225.
Lobelia, application of theory off — harmonic, 108; generally, 128-sampling
 to certain data, 269-270, 129 ; def., 128 ; calculation, 128;
272. is less than arithmetic and geo-Logarithmic
 increase of population, metric means, 129; difference
125-126 ; logarithmic mode, 128. from arithmetic mean in terms of
Lyon, T. L., refs., errors of agri- dispersion, (qu. 9) 156; use in
cultural experiment, 396. averaging prices if index-numbers,
129 ; in theory of sampling, when
MACALISTER, Sir DoNALD, ref., law numbers in samples vary, 264-265.
of geometric mean, 130, 314. — square error, 144.
Macdonell, W. R., data cited from,’ — weighted, 220-225; def., 220;
84, 90. difference between weighted and
March, L., refs., correlation, 208; unweighted means, 221-223 ; apindex-numbers,
 390, 391. plication of weighting to correc-Marriage-rate
 and trade, correlation tion of death-rates, ete., for ageof
 movements, 199-201. and sex-distribution, 223-225 ;
Marshall, A., Money Credit and Com- refs., 226.
merce, ref., 391. Median, 108; generally, 116-120 ;
Maxwell, Clerk, use of word ‘ sta- def., 116; indeterminate in certistical,”
 4. tain cases, 116-117 ; unsuited to
Mean, arithmetic, generally, 108- discontinuous observations and
116; def., 108-109; nature of, small series, 116-117 ; calculation
109 ; calculation of, for a grouped of, 117 ; graphical determination
distribution, 109-113; influence of, 118; comparison with arithof
 grouping, 113-114, 115, 116; metic mean, 119; advantages in
position relatively to mode and special cases, 119-120 ; slight inmedian,
 121-122, (refs.) 390; dia- fluence of outlying values on, 120 ;
grams, 113, 114; sum of devia- position relatively to mean and
tions from, is zero, 114 ; of series mode, 121-122, diagrams, 113,
compounded of others, 115; of 114, (refs.) 387; weighting of,
sum or difference, 115-116 ; com- 225 ; standard error of, 337-341.
parison with median, 119; sum-  Meitzen, P. A., refs., Geschichle,
mary comparison with median and Theorie wnd Technik der Statistik, 6.
mode, mean is the best for all. Mendelian breeding experiments as
oeneral purposes, 122-123 ; weight- illustrations, 37, 38, 128, 264-265,

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