Small businesses are viewed by many as the backbone of the U. S. economy. Small business owners are often described as entrepreneurs, requiring a variety of skills in order to be successful. A 2013 survey of small business owners found that the average age was 40 years. Suppose the Small Business Administration (SBA), which is a government agency that provides support to small businesses, would like to test the hypothesis that the average age of such businesses is now greater than 40 years. The Excel file labeled SBA. xlsx shows the ages of a recent sample of 100 small business owners. Using σ = 0.05, answer the following:

a. Perform a hypothesis test to determine if the average age of a small business owner exceeds 40 years.

b. Estimate the p value for this test using Table 5 in Appendix A.

c. Determine the precise p value for this test using Excel.

d. Use PHStat to validate these results.