Of the 45 people who have served as President of the United States since the office came into existence in 1789, 39 have died. Shown are the ages (in years) of the Presidents at the times of their deaths.

67 90 83 85 73 80 78 79

68 71 53 65 74 64 77 56

66 63 70 49 57 71 67 58

60 72 67 57 60 90 63 88

78 46 64 81 93 93 94

In the textbox below, answer the following questions

Does the data represent a population or a sample? (1 point)
Select a random sample of 12 ages and find the variance and standard deviation. I need to know the random sample you actually used to grade the questions below. (2 points)
Find the 95% confidence interval of the standard deviation. (2 points)
Find the standard deviation of all the data values. (2 points)
Does the confidence interval calculated in question 3 contain the standard deviation? (1 point)
If it does not, give a reason why. (1 point)
What assumption(s) must be considered for constructing the confidence interval in question 3? (1 point)