260 
Age at Marriage and Duratio7i of Life 
deaths in childbirth in order of confinement. This information is available for 
the nine years 1894 to 1902 and, together with the crude probability of death 
in each confinement, is shown in Table XIX. 
TABLE XIX. 
Probability of Death in Confinement. Experience of New South Wales, 1894—1902. 
Order of 
Confine- 
ment 
Births 
Deaths iu 
Confinement 
Probability 
of Death in ] 
Confinement j 
Order of 
Confinement 
Births 
Deaths in 
Confinement 
Probability of 
Death in 
Confinement 
1 
65778 
552 
■00839 
11 
4698 
46 
•00979 
3 
52818 
258 
■00488 
12 
2716 
34 
•01252 
3 
43462 
240 
■00552 
13 
1427 
24 
•01682 
Jf 
35510 
213 
■00600 
U 
703 
9 
•01280 
5 
28920 
204 
■00705 
15 
338 
6 
•01775 
6 
23527 
161 
•00684 
10 
129^ 
•007751 
7 
18729 
130 
■00694 
17 
«,n236 
•01471 1.Q,g95 
8 
14659 
132 
•00900 
18 
1\ 
•09524 j ^^^^^ 
9 
10580 
114 
■01078 
Beyond 18 
18j 
10 
7230 
1 
61 
•00844 
Rejecting the statistics of the sixteenth and subsequent confinements as 
being too limited to yield satisfactory results, the probabilities of death were 
graduated by means of a parabola of the fourtli order, the equation to which 
was found to be 
y = 8-384571 + -846415 x + -040384 x" - -002525 ai' + -000568 x\ 
where y = the probability of death, and x the number of confinement — the origin 
of the curve being at the eighth confinement. There are no points of inflexion, and 
the curve is convex throughout. The theoretical minimum occurs at the S-0954 
confinement. The statistics and curve will be found plotted on Fig. 9. Obtaining 
the probabilities of death from the parabola, we are enabled to ascertain the 
number of survivors of any given number of fertile married women at each 
confinement — presuming the mortality of childbirth to be the only operative 
cause of death. Thus adopting the symbols used in life tables*, calling x the 
number of confinement, the probability of death in the «th confinement, p^ 
the probability of surviving it, and l^, we have (taking 10,000 fertile married 
women) : 
X 
1x 
Px 
X 
9x 
1 
•00667 
•99333 
9933 
9 
•00927 
•99073 
9387 
2 
-00604 
•99396 
9873 
10 
■01027 
•98973 
9291 
3 
-00583 
•99417 
9815 
11 
■01127 
•98873 
9186 
4 
•00595 
•99405 
9757 
12 
■01240 
•98760 
9072 
5 
•00632 
•99368 
9695 
13 
■01367 
•98633 
8948 
0 
•00691 
•99309 
9628 
U 
•01511 
•98489 
8831 
7 
•00758 
•99242 
9555 
15 
•01679 
•98321 
8665 
8 
•00838 
•99162 
9475 
* 
Institute 0 
/ Actuaries 
Text Bonk, Part ii, p. 
xxi. 
