Discuss each of the following topics in class or review the topics on your own. Then write a brief but complete essay in which you summarize the main points. Please include formulas and graphs as appropriate.
1. In your own words, explain the differences among histograms, relative-frequency histograms, bar graphs, circle graphs, time-series graphs, Pareto charts, and stem-and-leaf displays. If you have nominal data, which graphic displays might be useful? What if you have ordinal, interval, or ratio data?
2. What do we mean when we say a histogram is skewed to the left? to the right? What is a bimodal histogram? Discuss the following statement: “A bimodal histogram usually results if we draw a sample from two populations at once.” Suppose you took a sample of weights of college football players and with this sample you included weights of cheerleaders. Do you think a histogram made from the combined weights would be bimodal? Explain.
3. Discuss the statement that stem-and-leaf displays are quick and easy to construct. How can we use a stem-and-leaf display to make the construction of a frequency table easier? How does a stem-and-leaf display help you spot extreme values quickly?

4. Go to the library and pick up a current issue of The Wall Street Journal, Newsweek, Time, USA Today, or other news media. Examine each newspaper or magazine for graphs of the types discussed in this chapter. List the variables used, method of data collection, and general types of conclusion drawn from the graphs. Another source for information is the Internet. Explore several web sites, and categorize the graphs you find as you did for the print media. For interesting web sites, visit the Brase/Brase statistics site at college.hmco.com/pic/braseUS9e and find links to the Social Statistics Briefing Room, to law enforcement, and to golf.