Page 395 The data plotted in Figure II.3 come from G. A. Sacher and E. F. Staffelt, “Relation of gestation time to brain weight for placental mammals: implications for the theory of vertebrate growth,” American Naturalist, 108 (1974), pp. 593–613. We found them in Fred L. Ramsey and Daniel W. Schafer, The Statistical Sleuth: A Course in Methods of Data Analysis, Duxbury Press, 1997, p. 228.

Page 397 Exercise II.23: For the gold prices, see http://kitco.com/charts/historicalgold.html.

Page 398 Exercise II.24: Antoni Basinski, “Almost never on Sunday: implications of the patterns of admission and discharge for common conditions,” Institute for Clinical Evaluative Sciences in Ontario, October 18, 1993.

Page 399 Exercise II.28: Official final election results are from the website of the Federal Election Commission, www.fec.gov.

Page 399 Exercise II.29: Correlations for 36 monthly returns ending in December 1999, reported in the Fidelity Insight newsletter for January 2000.