1. Of all U.S. credit unions, 67% have a "courtesy overdraft" policy that automatically covers overdrafts, with the median fee for each overdraft being approxi- mately $25. For 14 federal credit unions with a courtesy overdraft policy, the accompanying table shows their fee income, total assets, and average fee income per member
for 2008. Source: Kathy Chu, "Credit Unions Hit Customers with Fees, Too," USA Today, August 4, 2009, p. 2B.
Average Credit Fee Total Fee Income per
2. For the regression equation obtained in Exercise 16.19, analyze the residuals by (a) constructing a histogram, (b) utilizing the normal probability plot, and (c) plotting the residuals versus each of the independent
10 3.4 395.4 85.6
11 9.0 1249.8 54.6
12 6.8 986.0 93.3
13 2.5 417.5 76.6
14 0.2 178.4 18.1
a. Determine the multiple regression equation and inter- pret the partial regression coefficients.
b. Determine the 95% confidence interval for the population partial regression coefficients, f31 and f32.
c. Interpret the coefficient of determination and the result of each significance test done by the computer.
d. Analyze the residuals. Does the analysis support the applicability of the multiple regression model to these data?