solution

 

. Refer to the brokerage data in Exercise 11.23. Find the residuals for the multiple regression used to predict market share with number of accounts and assets as explanatory variables.

(a) Give a graphical summary of the distribution of the residuals. Are there any outliers in this distribution?

(b) Plot the residuals versus the number of accounts. Describe the plot and any unusual cases.

(c) Repeat part (b) with assets in place of number of accounts. Your analyses in Exercises 11.23 to 11.26 point to two firms,

Charles Schwab and Fidelity, as unusual in several respects. How influential are these firms? The following four exercises provide answers.