ealth care issues are receiving much attention in both academic and political arenas. A sociologist recently conducted a survey of citizens over 60 years of age whose net worth is too high to qualify for Medicaid. The ages of 14 senior citizens were as follows:

60

61

62

63

64

65

66

68

68

69

70

73

73

74


Calculate the standard deviation of the ages of the senior citizens correct to the nearest hundredth of a year.

5.13


5


4.61


5.4

1 answer

To calculate the standard deviation of the ages of the senior citizens, we first need to find the mean of the ages.

Mean = (60 + 61 + 62 + 63 + 64 + 65 + 66 + 68 + 68 + 69 + 70 + 73 + 73 + 74) / 14
Mean = 962 / 14
Mean = 68.71

Next, we need to find the squared difference between each age and the mean:

(60-68.71)^2 = 71.76
(61-68.71)^2 = 59.17
(62-68.71)^2 = 45.80
(63-68.71)^2 = 31.98
(64-68.71)^2 = 22.14
(65-68.71)^2 = 11.96
(66-68.71)^2 = 8.25
(68-68.71)^2 = 0.51
(68-68.71)^2 = 0.51
(69-68.71)^2 = 0.07
(70-68.71)^2 = 1.67
(73-68.71)^2 = 18.19
(73-68.71)^2 = 18.19
(74-68.71)^2 = 29.50

Now, sum up all of these squared differences:
71.76 + 59.17 + 45.80 + 31.98 + 22.14 + 11.96 + 8.25 + 0.51 + 0.51 + 0.07 + 1.67 + 18.19 + 18.19 + 29.50 = 318.20

Next, divide this sum by the number of ages (14), and then take the square root to find the standard deviation:

Standard Deviation = √(318.20 / 14)
Standard Deviation = √22.73
Standard Deviation ≈ 4.77

Therefore, the standard deviation of the ages of the senior citizens is 4.77 years, which rounded to the nearest hundredth would be 4.77.