EXPLANATION OF TABLES. 105 



EXPLANATION OF TABLES. 



I. Formulas. In this table the principal formulas used 

 in the calculation of curves are brought together for con- 

 venient reference. The meanings of the letters are explained 

 in the text. This table is preceded by an index to the prin- 

 cipal letters used in the formulae of this book. 



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. Th's 

 table is for comparison of a normal frequency polygon con- 

 sisting of weighted ordinates with the theoretical curve. 



Example: A = 17.673; o= 1.117; 2/ = 181.4. 

 (See page 26.) 



Entries in Table 

 V M corresponding to 



V V-M 7" V-M 2/0 y f 



a 



14 -3.673 3.29 .00449 X181.4 = 0.8 1 



15 -2.673 2.39 .05750 X 181.4 = 10.4 8 



16 -1.673 1.50 .32465 X 181.4 = 58.9 63 



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: A = 17.673; d = 1.1169. (See page 26.) 



