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作者：Hojo, T
摘要：The sampling distribution of the median is nearly normal in all cases; it gives a somewhat less reliable estimate of the population mean than the sample mean does. For very small samples there is little to choose in accuracy between the median and the center (mid-point of range). For large samples the center becomes relatively increasingly unreliable, while the standard error of the median has almost reached its limiting value when n = 20. The standard error of the mean is [image] (where a is ...
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作者：Pearson, K
摘要：The correlation of x, the mean of a sample, with z= (x [long dash]m)/[sigma], where m is the mean of the sampled population and [sigma] is the standard deviation of the sample, is high and approaches 1 as n, the number in the sample, increases. The regression is linear, but arrays of z are not homoscedastic. For n< 5, [beta]2''s of arrays of z are infinite. rz[sigma]-=0, but arrays of z for a given [sigma] are not homoscedastic. The z test is not so efficient even for small samples as some hav...
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作者：Pearson, ES
摘要：The author''s tables of the 5% and 1% points for V[beta]1 and [beta]2 in sampling from a normal population are not appreciably changed by substituting exact values of the moment-coefficients for the approximate values used in calculating the tables.
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作者：Pearson, ES
摘要：The results of experimental sampling suggest that the customary analysis of variance or test of the significance of n2 is adequate for a wide range of non-normal populations. In applying the test we shall not be liable to err by rejecting the hypothesis of a common origin of the groups when it is true. But in the more extreme cases of non-normal variation, there is danger of accepting the hypothesis when it is not true. The case in which the variation changes from group to group is not conside...
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作者：Neyman, J; Pearson, ES
摘要：The error in combining frequency groups for the x2 test is probably small if the groups contain only a small part of the total frequency. For small samples the test is also reasonably satisfactory. The difference between minimum x2 and the x2 of maximum likelihood is small.
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作者：Pearson, M; Pearson, K
摘要：In Pomeranians, Pekinese and crosses between them, the mean duration of pregnancy is about 60 days, and the standard deviation about 3 days. The correlation of size of litter with duration of pregnancy is [long dash].45 [plus or minus].05; with order of pregnancy, [long dash].05 [plus or minus].05; with age, [long dash].17 [plus or minus].06. In the first case, size of litter is probably the causal factor and hastens the end of gestation. The correlation of duration with order of pregnancy is ...
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作者：Kitson, E
摘要：This is based on 123 Teita skulls and 15 from a cave near the Naishi River. Measurements and type contours are given. Each series is homogeneous. The Teita skulls are small, especially in calvarial breadth, dolichocephalic and phenozygous. The Naishi River series have greater calvarial breadths. On the basis of the coefficient of racial likeness the Negro and allied races for which measurements are available are divided into 3 groups: (a) Congo, Cameroons, Gaboon, Negroes from Egypt, Galla and...
