Publisher's Synopsis
This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1918 edition. Excerpt: ...theory of the probable deviation. While it is not advisable to place implicit confidence in the tests furnished by the theory of probable deviations to the extent that the results which it indicates are accepted without some independent verification, or at least justification, yet when used with judgment it is an extremely valuable aid in practical statistical work. In every case it establishes cautionary limits, as, for instance, one would not ordinarily be justified in concluding that a variate with a deviation much greater than two or three times the standard deviation belonged to the distribution. On the other hand if a number of measurements of height should each consistently exceed those of the student distribution it might then be concluded with much certainty that the individuals measured were taken from a population distinctly different from the student population. And the conclusion would be justified even tho the deviations were considerably less than two or three times the standard deviation. CHAPTER VII. THE CORRELATION TABLE. From the records of the physical measurements a tabulation was made of the heights of the students whose weight was from 130 to 134 pounds--a weight class which may be denoted by the middle weight, 132 pounds--and the following distribution obtained: Height 62 63 64 65 66 67 68 69 70 71 72 73 74 Number 2 5 4 19 18 18 17 8 8 4 3 1 1 The distributions were likewise obtained for each other fivepound interval from 102 to 187 pounds. Instead of writing each of these distributions separately it is more convenient to write them together in one table called, for reasons explained on page 73, a correlation table. In this way we have Table VIII. The writing of the distributions in this compact tabular form...
