1) What is survival analysis used for? Please provide an example? (1 point)

2) What is the difference between hazard ratio and odds ratios? (1 point)

3) The national Labor survey of Youth (NLSY) collected information from 927 first-born children to mothers who chose to breast feed their child. Data were restricted to children born after 1978 and whose gestation was between 20 and 45 weeks. Table 1 shows the life table. The response variable in the dataset is the duration of breast feeding in weeks, followed by an indicator if the breast feeding is completed (i.e. the infant in weaned). Please complete the life table of weaning in the following considering 4 decimals. (2 points total; 1 point for 6^th column and 1point for the 7^th and 8^th column)

Table 1. Weaning from breast feeding

	ni	wi		di	qi=di/[ni-( wi/2)]	pi=1-qi	si=pipi-1pi-2...p1
Week Weaned	Number Entering this Interval	Number of withdrawn During Interval	Number exposed to weaning	Number of weaned	Prpn Terminating	Propn Surviving	Cumul Prop Surv at End
0-2	927	2	926	77
2-3	848	3	846.5	71
3-5	774	6	771	119
5-7	649	9	644.5	75
7- 11	565	7	561.5	109
11-17	449	5	446.5	148
17-25	296	3	294.5	107
25-37	186	0	186	74
37-53	112	0	112	85
53-	27	0	27	27

4) In a few sentences, please describe your findings from Table 1 above. (1 point)