374 PONTIFICIAE ACADEMIAE SCIENTIARVM SCRIPTA VARIA - 28 
It is really remarkable that the II curves, which relate to 
he mixed model, stay very near to the I curves of the expo- 
nential model, even though the weight attributed to the expo- 
aential element is but 2/3. This is due to the fact that the 
coefficient A in the mixed model has a value very near that 
which it takes in the exponential model, so that the 3(8) funct- 
ions of model I and II have approximately the same three first 
moments (1). 
General Comments 
540. It is certainly very surprising at first sight to find that 
for small values of w and for large values of n, the model 
considered has very different properties from those of the 
exponential and para-exponential models, though for w=o it 
is identical to the exponential model and for w=1 identical to 
the para-exponential model. 
For the first and second, for example, 
4 
B ~ i. 
for 
1-0=4% 
whereas for w=o0.10 and # sufficiently great, À has a value 
very near 5, and ®_ can even become greater than any value (). 
It may first be noted that no illusions should be had about 
small values of w, since large values of n can have a greater 
influence, with correspondingly greater deviation of the model 
irom the exponential. 
A 4 336. 
(?) $ 532 and 535. 
‘'11] Allais - pag. 278