A. O. POWYS 
235 
FiQ. 2. Length of Life of Married Women and Size of Familj'. Experience of New South Wales, 
1898—1902. 
1' 
c 
a' 
// 
< 
15 20 25 30 35 40 45 60 55 60 65 70 75 
Ages of Married Women at Death. 
Equation to Regression Straight Line aa', - 3-7179 + -21729.1: 
hb', ij= 3-6866 + -04336.r 
» cC 
100 105 
Origin at Birth. 
Unit of = 1 year. 
?/= 8-1656- ■02-5366.r 
Cuhical Parabola dd' , y = 6-29315 + -15595.!- - •04839.r2+ -00199.; 
(Origin at 60 years. 
(Unit of X = o years. 
(a) from age period 20 — 25 to 50— 55, and (6) from 55 — 00 to 95—100. The obser- 
vations beyond age 100 are too few to attach much weight to tlie results. From 
Fig. 2 it is seen that the female statistics divide into three well-defined series, 
(a) from age group 15 — 20 to 40 — 45, (b) from 40 — 45 to 65 — 70, and (c) from 
65 — 70 to 100—105. These divisions in each sex are practically in agreement 
with those of Professor Pearson's English and American Quaker families* — more 
especially the former — although owing to the comparative paucity of data, his series 
are not so well defined. The New South Wales data for ages beyond 75 are 
sufficiently extensive to furnish reliable results up to age 100. 
The correlation between the duration of life and number of offspring and 
the regression straight lines have been determined for each of the five series 
and the general results are set forth in Tables III. and IV. 
TABLE III. General Results. 
Parent 
Period of 
Life 
Mean Age 
at Death 
(years) 
Mean Size 
of Family 
Standard 
Deviation 
Age at 1 Size of 
Deathsfj Family 
Correlation 
between Duration 
of Life and 
Fertility 
Regression 
Probable 
error of y 
(Size of 
Family) 
Father 
Under 60 
45-3424 
4-3216 
1-8434 
1-4266 
•99436+ -00013 
+ -76954 
+ -1020 
)) 
60 and over 
70-90975 
6-3369 
1 -9050 
-2304 
-54915+ -00698 
+ -06642 
+ •1299 
Mother 
Under ^5 
33-6208 
3-6484 
1 -3226 
1 -4436 
•99541 + -00009 
+ 1 -08645 
+ -0931 
45 to 70 
56-0605 
6-1168 
1 -7563 
-3877 
-98178+ -00029 
+ -21675 
+ -14.50 
» 
70 and over 
76-4400 
6-2166 
1 -4935 
•2205 
- ^85910+ -00824 
- -12683 
* "Data for the Problem of Evolution in Man. V. On the Correlation between the Duration of 
Life and the Number of Offspring." Beeton, Yule and Pearson, E. S. Proc. Vol. lxvii. pp. 161 — 179. 
t Unit of Standard Deviation of Age at Death is 5 years. 
30—2 
