5* 



Tables 27-29 

 LEAST SQUARES 



TABLE 27.— Values of the factor 0.6745 



\»(n— 1) 



for the probable error of the 



arithmetical mean. 



TABLE 28. — Values of the factor 0.8453 



\ w(n-l) 



This factor occurs in the approximate equation r= 0.8453 



\(n (»— 1) 



for the probable error of a single observation. 



TABLE 29.— Values of 0.8453 



2|«| 



■mjn—l 



This factor occurs in the approximate equation >o=o.8453 — ■ - for the probable error of the arithmetical mean. 



n\n — 1 



Smithsonian Tables. 



