Refer to given Exercise. Test the null hypothesis of equality of the survival functions of the two groups using a level of significance of 0.05.
Exercise
Two groups of samples of patients were randomly selected from a county. The first group (Group 1) had no history of a chronic disease while the second group (Group 2) had a positive history. The selected patients were observed for a period of 15 years. Some patients had to leave the study due to relocation or other reasons while some survived the total observation period. The censored survival times for such patients are indicated by a "+" after the listed time.
Given Table shows the survival times for patients in each group. Find the estimated survival function for patients in each group.
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TABLE : Survival Time of Patients
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Group 1, No Chronic Disease
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Group 2, Chronic Disease
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4, 5, 5, 6+, 8, 10, 12+,
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2, 3, 3, 4, 6, 7+, 8,
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13+, 13, 14, 14, 15, 15+,
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8, 9+, 9, 10, 10, 11, 12+,
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15+, 15+
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13, 14+, 14, 14, 15, 15
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