ISSN:0162-1459    

DOI:10.1080/01621459.1946.10501860

出版商:Taylor & Francis Group    

年代:1946

数据来源: Taylor

ISSN:0162-1459    

DOI:10.1080/01621459.1946.10501861

出版商:Taylor & Francis Group    

年代:1946

数据来源: Taylor

摘要:

In business sampling, as in the general sampling problem, the over-all test that we apply to a sample design is that it shall yield the desired information with the reliability required at a minimum cost; or, conversely, that at a given cost it shall yield the estimates desired with the maximum reliability possible. A second criterion which we impose on the sample design is that the reliability of the sample results should be measurable. This requirement eliminates from consideration many superficially attractive sampling schemes which, while generally economical in both time and money, may lead to faulty conclusions.

ISSN:0162-1459    

DOI:10.1080/01621459.1946.10501862

出版商:Taylor & Francis Group    

年代:1946

数据来源: Taylor

摘要:

This study describes the actuarial methods used to determine the probable service life of the R-3350 engines used in B-29 aircraft. The use of actuarial methods to determine the expectation of life of engines under actual operating conditions is clearly superior to that of using averages based on the flying hours attained solely by engines removed for overhaul. This superiority is greatest when the engine “age” distribution or operating conditions are changing.

ISSN:0162-1459    

DOI:10.1080/01621459.1946.10501863

出版商:Taylor & Francis Group    

年代:1946

数据来源: Taylor

摘要:

This paper presents a simple introduction to the theory of systematic sampling. Its relation to random sampling, stratified random sampling and cluster sampling is shown by means of a numerical example. Some advice is given on the circumstances under which systematic sampling may be advantageously used.

ISSN:0162-1459    

DOI:10.1080/01621459.1946.10501864

出版商:Taylor & Francis Group    

年代:1946

数据来源: Taylor

摘要:

This note presents a short procedure for calculating the geometric mean from a large amount of data. The method involves a) using a grouping of the frequency distribution such that the ratios of the class limits are equal, and b) an application of the “short method” for calculating the arithmetic average. By this procedure the calculation of the geometric mean takes more time than that of the arithmetic mean, only to the extent of getting the logarithms of four values and the antilog-arithm of one value. Analogous procedure can be used for the harmonic and other means.

ISSN:0162-1459    

DOI:10.1080/01621459.1946.10501865

出版商:Taylor & Francis Group    

年代:1946

数据来源: Taylor

摘要:

The purpose of this paper is to outline the principles and use of a method for sampling factors—such as the amount of rain reaching the ground under a forest during a series of storms—which exhibit variations in both space and time. Solutions of two somewhat different sampling problems are discussed. One is designed simply to provide a sample estimate (average or sum) for any desired factor over a period of time. The other, with little loss of efficiency, provides a sample estimate for each of a series of short time units making up the period, as well as an estimate for the period as a whole. It is shown that these sampling methods are likely to supply a substantial gain in efficiency as compared to methods that have been commonly employed.

ISSN:0162-1459    

DOI:10.1080/01621459.1946.10501866

出版商:Taylor & Francis Group    

年代:1946

数据来源: Taylor

ISSN:0162-1459    

DOI:10.1080/01621459.1946.10501867

出版商:Taylor & Francis Group    

年代:1946

数据来源: Taylor

ISSN:0162-1459    

DOI:10.1080/01621459.1946.10501868

出版商:Taylor & Francis Group    

年代:1946

数据来源: Taylor

ISSN:0162-1459    

DOI:10.1080/01621459.1946.10501869

出版商:Taylor & Francis Group    

年代:1946

数据来源: Taylor