For Questions 19-20 use the following information:

You are the principal investigator of a four-year survival study. Unfortunately, your new research assistant went on vacation without filling in the important calculation fields in the life table below. In order to discover how effective your study was, you must fill out the ACTUARIAL life table and interpret the data.

Table 4.

Interval since start of study	Number alive at start of interval	Number who were censored during interval e.g., (lost to follow-up, etc)	Adjusted number at risk during interval (Number alive at midpoint)	Number who died during interval	Proportion who died during interval	Proportion who survived during interval	Cumulative proportion who survived from enrollment to end of interval (Cumulative survival)
1st year	100	5	Question 19	4
2nd year	91	3		7
3rd year	81	3		6
4th year	72	5		9			Question 20

Question 19

What is the adjusted number at risk at 1^st year since the start of the study? Report your answer rounded to the 10^th decimal place.

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Question 20

What is the cumulative survival at the end of the 4th year among participants of this study (using the life table)? Please give your answer as a percentage (multiply by 100) rounded to the 10^th decimal place. (i.e.: 14.1%)

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