Performance of stock screeners. Refer to the American

QUESTION:

Problem 64E

Performance of stock screeners. Refer to the American Association of Individual Investors (AAII) statistics on stock screeners, Exercise 2.42 (p. 70). Annualized percentage return on investment (as compared to the Standard & Poor’s 500 Index) for 13 randomly selected stock screeners are reproduced in the table.

a. Find the range of the data for the 13 stock screeners. Give the units of measurement for the range.

b. Find the variance of the data for the 13 stock screeners. If possible, give the units of measurement for the variance.

c. Find the standard deviation of the data for the 13 stock screeners. Give the units of measurement for the standard deviation.

2.42 Performance of stock screeners. Investment companies provide their clients with automated tools—called stock screeners—to help them select a portfolio of stocks to invest in. The American Association of Individual Investors (AAII) provides statistics on stock screeners at its Web site, www.aaii.com. The next table lists the annualized percentage return on investment (as compared to the Standard & Poor’s 500 Index) for 13 randomly selected stock screeners. (Note: A negative annualized return reflects a stock portfolio that performed worse than the S&P 500.)

9.0 -.1 -1.6 14.6 16.0 7.7 19.9 9.8 3.2 24.8 17.6 10.7 9.1

a. Compute the mean for the data set. Interpret its value.

b. Compute the median for the data set. Interpret its value.