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7. Probability and Statistics Soviet Essays - Sheynin, Oscar

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for finite values of N, M <strong>and</strong> R 2 . For M = R precise <strong>and</strong> rather simple formulas for thedistributions D N,N , D N,N + <strong>and</strong> for their joint distribution were {also} derived (Gnedenko &Koroliuk [60], Gnedenko & Rvacheva [64]). Koroliuk [6] determined the distributionfunctions of D M,R <strong>and</strong> D M,R + . For M = pR, assuming that p , he derived the distribution ofthe statistics D N + <strong>and</strong> D N . Rvacheva [8], also see Gnedenko [79], considered the maximaldiscrepancy between two empirical distributions not on all the axis, but on an assignedstochastic {r<strong>and</strong>om?} interval. The works of Ozols [1; 2] adjoin these investigations.In addition to the listed issues, problems concerning the mutual location of two empiricaldistribution functions were also considered. Such, for example, was the problem about thenumber of jumps experienced by the function F M (x) <strong>and</strong> occurring above F R (x). Gnedenko &Mikhalevich [68; 69] studied the case M = pR, <strong>and</strong> Paivin (Smirnov’s student) considered thegeneral case ({although} only its limiting outcome). Mikhalevich [3] derived the distributionof the number of intersections of the function F M (x) with the broken liney = F R (x) + zM + RMRfor M = R; also see Gnedenko [79].The test of a hypothesis that a distribution belongs to a given class of distributions presentsa more general problem than that of testing the agreement between empirical data <strong>and</strong> aprecisely known distribution function. The mentioned class of distributions can, for example,depend in a definite way on a finite number of parameters. Gikhman [13; 16; 17] initiatedsuch investigations by studying these problems for the Kolmogorov <strong>and</strong> the 2 tests. Atabout the same time Darling (1955) examined similar problems for the latter test.The investigation of the 2 goodness-of-fit test for continuous distributions <strong>and</strong> anunbounded increase both in the number of observations <strong>and</strong> in the intervals of the grouping isrelated to the issues under discussion. Tumnanian’s [1] <strong>and</strong> Gikhman’s [19] findings belongto this direction. We only note that this problem is akin to estimating densities.5. During the last years, a considerable number of studies were devoted to developingstatistical methods of quality control of mass manufactured goods. These investigationsfollowed three directions: empirical studies; development of methods of routine control; <strong>and</strong>the same for acceptance inspection. Drawing on these works, Tashkent mathematiciansworked out a draft State st<strong>and</strong>ard for acceptance inspection based on single sampling. Suchissues are important for practice, <strong>and</strong> several conferences held in Moscow, Leningrad, Kiev<strong>and</strong> other cities were devoted to them.Contributions on routine statistical control were mostly of an applied nature; as a rule, theydid not consider general theoretic propositions. The investigations of Gnedenko, Koroliuk,Rvacheva <strong>and</strong> others (§4) nevertheless assumed these very contributions as a point ofdeparture. In most cases the numerous methods of routine statistical quality control offeredby different researchers regrettably remained without sufficient theoretical foundation. Thus,an analysis of their comparative advantages <strong>and</strong> economic preferences is still lacking. Fromthe mathematical point of view, the method of grouping proposed by Fein, Gostev & Model[1] is perhaps developed most of all. Romanovsky [117] <strong>and</strong> Egudin [7] worked out itstheory <strong>and</strong> Bolshev [1; 2] suggested a simple nomogram for the pertinent calculations.Egudin provided vast tables adapted for practical use <strong>and</strong> Baiburov [1] with a number ofcollaborators constructed several appropriate devices {?}.A number of scientists investigated problems of acceptance inspection, but we only dwellon some findings. As stated above, Kolmogorov [129] applied the idea of unbiased estimatesfor such inspection. He assumed that one qualitative indicator was inspected after which the

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