Can the combined median be calculated from the medians for each number of members? Gov.

a. Discuss the appropriateness of using the sample mean to describe these two

variables.

b. Compute the sample mean, 10 trimmed mean, and 20 trimmed mean. Which

trimmed mean seems more appropriate for each variable? Why?

c. Does there appear to be a relation between the number of plants destroyed and the

number of arrests? How might you examine this question? What other variables might be related to the number of plants destroyed? Bus. 3.58 The most widely reported index of the performance of the New York Stock Exchange NYSE is the Dow Jones Industrial Average DJIA. This index is computed from the stock prices of 30 companies. When the DJIA was invented in 1896, the index was the average price of 12 stocks. The index was modified over the years as new companies were added and dropped from the index and was also altered to reflect when a company splits its stock. The closing New York Stock Exchange NYSE prices for the 30 components as of May 2004 of the DJIA are given in the following table. a. Compute the average price of the 30 stock prices in the DJIA. b. Compute the range of the 30 stock prices in the DJIA.

c. The DJIA is no longer an average; the name includes the word “average” only for his-

torical reasons. The index is computed by summing the stock prices and dividing by a constant, which is changed as stocks are added or removed from the index and when stocks split. where y i is the closing price for stock i, and C ⫽ .1409017. Using the stock prices given, compute the DJIA for May 27, 2004.

d. The DJIA is a summary of data. Does the DJIA provide information about a popula-

tion using sampled data? If so, to what population? Is the sample a random sample? Components of DJIA NYSE Stock Company Percent of DJIA Price 52704 3M Co. 5.9078 84.95 Alcoa Inc. 2.1642 31.12 Altria Group Inc. 3.3673 48.42 American Express Co. 3.5482 51.02 American International Group Inc. 5.0628 72.8 Boeing Co. 3.213 46.2 Caterpillar Inc. 5.2277 75.17 Citigroup Inc. 3.2352 46.52 Coca-Cola Co. 3.569 51.32 E.I. DuPont de Numours Co. 3.0057 43.22 Exxon Mobil Corp. 3.0161 43.37 General Electric Co. 2.174 31.26 General Motors Corp. 3.1601 45.44 Hewlett-Packard Co. 1.4702 21.14 Home Depot Inc. 2.4925 35.84 Honeywell International Inc. 2.3499 33.79 Intel Corp. 1.9785 28.45 International Business Machines Corp. 6.1609 88.59 J.P. Morgan Chase Co. 2.5697 36.95 Johnson Johnson 3.8799 55.79 McDonald’s Corp. 1.8269 26.27 Merck Co. Inc. 3.2985 47.43 DJIA ⫽ a 30 i⫽1 y i C continued Components of DJIA NYSE Stock Company Percent of DJIA Price 52704 Microsoft Corp. 1.8214 26.19 Pfizer Inc. 2.4619 35.4 Procter Gamble Co. 7.5511 108.58 SBC Communications Inc. 1.6586 23.85 United Technologies Corp. 5.848 84.09 Verizon Communications Inc. 2.4396 35.08 Wal-Mart Stores Inc. 3.8924 55.97 Walt Disney Co. 1.6489 23.71 H.R. 3.59 As one part of a review of middle-manager selection procedures, a study was made of the relation between hiring source promoted from within, hired from related business, hired from unrelated business and the 3-year job history additional promotion, same position, resigned, dismissed. The data for 120 middle managers follow. Source Job History Within Firm Related Business Unrelated Business Total Promoted 13 4 10 27 Same position 32 8 18 58 Resigned 9 6 10 25 Dismissed 3 3 4 10 Total 57 21 42 120 a. Calculate job-history percentages within each source. b. Would you say that there is a strong dependence between source and job history? Env. 3.60 A survey was taken of 150 residents of major coal-producing states, 200 residents of major oil- and natural-gas–producing states, and 450 residents of other states. Each resident chose a most preferred national energy policy. The results are shown in the following SPSS printout. STATE COUNT ROW PCT COAL OIL AND OTHER ROW COL PCT GAS TOTAL TOT PCT OPINION 62 25 102 189 COAL ENCOURAGED 32.8 13.2 54.0 23.6 41.3 12.5 22.7 7.8 3.1 12.8 3

12 26

41 FUSION DEVELOP 7.3 29.3 63.4 5.1 2.0 6.0 5.8 0.4 1.5 3.3 8 6

22 36

NUCLEAR DEVELOP 22.2 16.7 61.1 4.5 5.3 3.0 4.9 1.0 0.8 2.8 19 79 53 151 OIL DEREGULATION 12.6 52.3 35.1 18.9 12.7 39.5 11.8 2.4 9.9 6.6