202 



NATURAL INHERITANCE. 



Tables 4 to 8 inclusive give data for drawing Normal Curves 

 of Frequency and Distribution. They also show the way in 

 which the latter is derived from, the values of the Probability 

 Integral. 



The equation for the Probablity Curve 1 is y = k e in which 



h is "the Measure of Precision." By taking h and h each as 

 unity, the values in Table 4 are computed. 



Table 4. 

 Data for a Normal Curve of Frequency. 



-X' 2 



y= c 



X 



y 



X 



y 



X 



y 



X 



y 







TOO 



± 10 



0-37 



± 2-0 



0-0183 



± 3-0 



o-oooi 



± 0-2 



0-96 



± 1-2 



0-23 



± 2-2 



0-0079 







± 0-4 



0-85 



± 1-4 



0-14 



± 2-4 



0-0032 



± infi- 



o-oooo 



± 0-6 



0-70 



± 1-6 



0-78 



±2-6 



0-0012 



nity 



± 0-8 



0-53 



± 1-8 



0-40 



± 2-8 



0-0004 







Table 5. 



2 r* — (2 



Values of the Probability Integra], — = J e dt, for Argument t. 



t {=hx) 



•o -l 



•2 



•3 



•4 



•5 



•6 



•7 



•8 



•9 







1-0 

 2-0 



infinite 



o-oo 



0-843 

 •9953 



1-0000 



0-11 



0-880 



•9970 



0-22 



910 

 •9981 



0-33 



0-934 



■9989 



0-43 



0-952 



•9993 



0-52 



0-966 



•9996 



0-60 



0-976 



•9998 



0-68 

 0-984 

 9999 



0-74 

 9S9 

 •9999 



0-80 



0-923 



•9999 





"When t = '4769 the corresponding tabular entry would be -50 ; 

 therefore, -4769 is the value of the " Probable Error." 



1 See Merriman On the Method of Least Squares (Macmillan, 1885), pp. 26, 186, 

 where fuller Tables than 4, 5, and 6 will be found 



