# Forbes magazine published data on the best small firms in 2012. These were firms that had been publicly traded for at least a year, have a stockprice of at least \$5 per share, and have reported annual revenue between \$5 million and \$1 billion. The table below shows the ages of the corporateCEOS for a random sample of these firms.48 58 5161565974635350596060574663 57554755574361624967 55675549Use this sample data to construct a 90% confidence interval for the mean age of CEO's for these top small firms. Use the Student's t-distribution(a) what is the lower bound for 90% confidence interval for the mean age of CEO's? (Round to 3decimal places)UESTION 32(b) What is the upper bound (Round to 3 decimla places)

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Step 1

The formula for 90% confidence interval for the mean age of CEO’s is given as

Step 2

The sample mean and standard deviation can be obtained using Excel:

• Enter the data into Excel file.
• Enter “= AVERAGE (A1:A30)” to get the sample mean as 56.56
• Enter “=STDEV.S (A1:A30)” to get the sample variance as 6. 90.
Step 3

The degrees of freedom corresponding to t distribution is n – 1.

That is, the degrees of freedom is, 29 (=30&ndas...

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