EXPLANATION OF TABLES. 43 



EXPLANATION OF TABLES. 



I. Formulas. In this table the principal formulas used 

 in the calculation of curves are brought together for conven- 

 ient reference. The meanings of the letters are explained in 

 the text. 



II. Certain constants and their logarithms. 



This table includes the constants most frequently employed 

 in the calculations of this book. 



III. Table of ordinates of normal curve. This 

 table is for comparison of a normal frequency polygon con- 

 sisting of weighted ordinates with the theoretical curve. 



Example: M = 14.157 ; a = 0.604 ; ly<> = 1255. 

 (See page 19.) 



Entries in Table 

 V - M corresponding to 

 V V-M V- M 2/o y f 



a 



11 - 3.157 5.2 .000004 X 1255 = 0.0 1 



12 - 2.157 3.6 .0015 X 1255 = 1.8 2 



13 - 1.157 1.9 .164 X 1255 = 201 8 189 



IV. Table of values of probability integral. 



This table is for comparison of a normal frequency polygon 

 consisting of rectangles with the theoretical curve. 

 Example: M. 5.24 ; cr = 0.987. (See page 12). 



