Question

You decide to study the life history of Yangtze finless porpoises for your PhD. You enroll at the Chinese Academy of Sciences and follow a cohort of porpoise through their lives. During the first season, you find 68 pregnant porpoises and when they give birth, you insert a chip in the babies. You return every year, capture your marked baby porpoises, and determine how many are still alive. Based on this, complete the attached life table:

Porpoise Age (years)	Nx	lx	dx	qx
0	68
1	12
2	10
3	8
4	7
5	3
6	0

Answer 1

Answer = Formulas for calculation are as follows:

lx = survivorship in year x = Nx / n0

= 68 /68 =1

dx = nx - nx  + 1

= 68 -12 =56

qx = dx/nx

Porpoise Age (years)	Nx	lx	dx dx = nx - nx  + 1	qx qx = dx/nx
0	68	1	56	0.82
1	12	0.17	2	0.16
2	10	0.147	2	0.2
3	8	0.117	1	0.125
4	7	0.102	4	0.57
5	3	0.044	3	1
6	0	0	0	0