# Determining the 95% Conf. Interval Estimates of the Mean

12.3-question 1

A statistics practitioner has been given the task of making these predictions. Accordingly, random samples of four groups of Canadians were drawn. They are

Group Ages

1 45-64

2 65-74

3 75-84

4 85 and over

Age group 2011 2016 2021 2026 2031

45-64 9718 10013 10065 9996 10016

65-74 2644 3344 3992 4511 4846

75-84 1600 1718 2045 2627 3169

85+ 639 738 810 909 1121

The medical expenses for the previous 12 months were recorded and stored in columns 1 to 4 in c12-03. Projections for 2011, 2016, 2021,2026 and 2031 of the numbers of Canadians (in thousands) in each age category are listed above.

a) Determine the 95% confidence interval estimates of the mean medical costs for each of the four age categories.

b) For each year listed, determine the 95% confidence interval estimates of the total medical costs for Canadians 45 years old and older.

https://brainmass.com/statistics/confidence-interval/determining-the-95-conf-interval-estimates-of-the-mean-248679

#### Solution Preview

Dear Student,

I used Excel's statistical tool to solve the problem. This is how you do it in Excel:

Go to Tools --> Data Analysis --> Descriptive Statistics

Please note that, you can also calculate ...

#### Solution Summary

The solution provides two different step by step methods of creating 95% confidence interval estimates of the mean in Excel.