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. 



^2^2 



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



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

 unity, the values in Table 4 are computed. 



TABLE 4. 

 Data for a Normal Curve of Frequency. 



TABLE 5. 



2 r' j2 



Values of the Probability Integra], = I e " dt, for Argument t. 



\/itJ 



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 



