These firms and industries display considerable variation in risk and returns.Several other data file are in the CHAP2.DAT subdirectory, such as GOLD, EVENTS, and APM. The contents of those data files are discussed in the exercises below.
At numerous times in the following exercises we will ask you to test an hypothesis using a "reasonable level of significance." Since what is "reasonable" is to some extent discretionary, you are asked to follow the convention of stating precisely what percent significance level is being used to test hypotheses; in that way, others with different preferences can still draw their owe inferences.