USA Today reported that the state with the longest mean life span is Hawaii, where the population mean life span is 77 years.

A random sample of 20 obituary notices in the Honolulu Advertiser 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

years and s < 20.65 years.

Assuming that life span in Honolulu is approximately normally distributed, does this information indicate that the population mean life span for Honolulu residents is less than 77 years by answering the following:

a) What are the null and alternate hypotheses, H₀and H_1?

b) What sampling distribution should be used (z or t)? Why? Calculate the statisticfor this data sample.

c) Use a 5% level of significance -to determine the critical value.

d) Is the alternate hypothesis valid at this significance level.

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