Insurance companies track life expectancy information to assist in determining the cost of life insurance policies. You work for an insurance company and know that, last year, the life expectancy of your policy holders was 77 years. You have been asked to perform a study to decide if the company premium structure should be changed, or stay the same. Should you find evidence that policyholders are living longer, you would recommend a change in the premium structure. Your conclusion will be based on a 90% confidence interval.

You have randomly selected 20 recently paid policies and noted the age at which those individuals passed:

86	75	83	84	81	77	78	79	79	81
76	85	70	76	79	81	73	74	72	83

Make a fictitious email that you would send your boss that relays the necessary information taken into account to accurately perform your confidence interval calculation and state the conclusion you have drawn based on that interval. For grading purposes, show all work in the calculation.