The U. S. Census Bureau would like to estimate the average annual contributions to charity by the members of Generation Y (people born in the United States in the years 1981 through 1991). The following data show the annual contributions to charity for a random sample of 18 individuals in this age group. These data can also be found in the Excel file titled contributions. xlsx.
a. Construct a 95% confidence interval with these data to estimate the average annual contributions to charity for this age group.
b. What is the margin of error for this sample?
c. Verify your results using Excel.