Question

1. (16 pts.) We have divided the data into the following age classes: 0-9, 10-19, 20-29, etc. in 10 year groups. For example, if someone was born in 1855 and died in 1865, we will assume that they lived for 10+ years and belong in the 10-19 age class.

a. Complete the table in the excel spreadsheet by determining separate lx for each sex and each age class (x).

b. Construct a graph showing separate survivorship curves for each gender on the same graph. Label the axes clearly and correctly.

c. Are these type I, II, or III survivorship curves? How can you tell?

d. Note and explain 3 major differences between the male and female survivorship curves.

Complete the life table

Age Range	x	Number of famales	lx for females	number of males	lx for males
0-9	0	65		87
10-19	10	63		78
20-29	20	58		75
30-39	30	47		69
40-49	40	44		60
50-59	50	40		50
60-69	60	33		40
70-79	70	25		22
80-89	80	18		5
90-99	90	3		1
100-110	100	0		0
110+	110	0		0

Answer 1

a)

nx ( female )	Ix	nx ( male)	Ix
65	1	87	1
63	0.9	78	0.8
58	0.8	75	0.8
47	0.7	69	0.7
44	0.6	60	0.6
40	0.6	50	0.5
33	0.5	40	0.4
25	0.3	22	0.2
18	0.2	5	0.05
3	0.04	1	0.01
0	0	0	0
0	0	0	0

b)

c ) this type of survivroship curve is type II survivorship curve because of constant death rate . whereas type I show late loss and type III show eraly loss. Type II curve is more common in birds.

d) (i) constant Ix between male and female at age 20 to 40.

(ii) difference in Ix from age 40 to 90.

(iii) at age 20 male show 0.8 Ix and female show 0.9 Ix.

I x of female is more than male at each age group.