Question

A national newspaper reported that the state with the longest mean life span is Hawaii, where the population mean life span is 76 years. A random sample of 20 obituary notices in the Honolulu Advertizer gave the following information about life span (in years) of Honolulu residents.

72 68 81 93 56 19 78 94 83 84 77 69 85 97 75 71 86 47 66 27

Use a calculator with sample mean and standard deviation keys to find x and s.

Answer 1

Answer: x = 71.4

s = 20.13

Explanation:

The mean of the set of data given is

Mean = (72 + 68 + 81 + 93 + 56 + 19 + 78 + 94 + 83 + 84 + 77 + 69 + 85 + 97 + 75 + 71 + 86 + 47 + 66 + 27)/20 = 71.4

Standard deviation = √(summation(x - mean)/n

n = 20

Summation(x - mean) = (72 - 71.4)^2+ (68 - 71.4)^2 + (81 - 71.4)^2 + (93 - 71.4)^2 + (56 - 71.4)^2 + (19 - 71.4)^2 + (78 - 71.4)^2 + (94 - 71.4)^2 + (83 - 71.4)^2) + (84 - 71.4)^2 + (77 - 71.4)^2 + (69 - 71.4)^2 + (85 - 71.4)^2 + (97 - 71.4)^2 + (75 - 71.4)^2 + (71 - 71.4)^2 + (86 - 71.4)^2 + (47 - 71.4)^2 + (66 - 71.4)^2 + (27 - 71.4)^2 = 8100.8

Standard deviation = √(8100.8/20) = 20.13