XIV.—REMOVING LIMITATIONS OF SIMPLE SAMPLING. 283 
TABLE showing Frequencies of Registration Districts in England and Wales 
with Different Proportions of Deaths in Childbirth (including Deaths 
Jrom Puerperal Fever) per 1000 Births in the same Year, for the same 
Groups of Districts as in the Table of Chap. XIII. § 10. Data from same 
source. Decade 1881-90. 
Number of Births in the Decade. 
Deaths in 
Childbirth per 1509 | 3500 | 4500 | 10,000 15,000 | 30,000 | 50,000 
1000 Births. to | to | to 0 to to . to 
2500. 1 4000. | 5000. 15,000. 20,000. ' 50,000, 90,000. 
1'5- 20 t > = — = 
20- 2°5 ~ Be a 
2+'5- 30 os 
3'0- 35 : - - 
3'5- 4°0 
4'0- 45 2. 
4:5- 50 7 
5'0- 5'5 
55-60 
$:0- 65 
6'56—- 70 
70-75 = 
7'5- 8°0 : 
8:0- 85 2 
8+5—- 90 
9°0- 95 
9+5-10°0 
100-105 
105-110 
Total : Ld i SE 73 33 35 
Shona Fron I 10:5 438 499 |  . = 4-64 
tandard-de-, , . , . ¥ ’ : z . 
Y tiation } 199, 101 0:99 | 112 087 
Theoretical) 
standard -de- 
viationcorre- | 1-52 | 112 | 097 | 061 053 036 0-26 
sponding to 
mean births 
A/s2—52 071 | 0-80 | 051 | 030 , ¢°4 | 107 | 083 
| 
and hence, knowing s and s,, we can find o, the standard-deviation 
of the chance or proportion in the universes from which the 
samples have been drawn. 
The values of \/s*—s; are tabulated at the foot of the table 
showing the distribution of the proportion of male births in