184 
On Criminal Anthropometry 
The mode is 480 574 and occurs at a; = ri05291, corresponding to a height of 
65"-4774 ; the mean occurs at x = 1-163362, its value being 65"-5355. 
This curve also is very nearly normal. Both curves are drawn on Figs. 3 and 4, 
which bring out clearly the closeness of the two curves to each other. 
Fig. 3. Head Breadth in Criminals. 
I 
1 / 
dj— 
n 
// 
-ff 
5 
r 

Iff 
V 
7 
150 
l^O 150 ±60 
Head Breadth in mm. 
Skew Curve Normal Curve 
vo 
Seeing that the regression lines are closely linear, and the frequency curves 
closely normal, we may assert that the distribution is at any rate very approxi- 
mately normal. This is an important result, as it gives us confidence in applying 
Professor Pearson's abbreviated method, based as it is on the assumption of normal 
frequency. 
