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U.S. Regions. The U.S. Census Bureau divides the states in the United States into four regions: Northeast (NE), Midwest (MW), South (SO), and West (WE). The following table gives the region of each of the $50$states.

Road Rage. The report Controlling Road Rage: A Literature Review and Pilot Study was prepared for the AAA Foundation for Traffic Safety by D. Rathbone and J. Huckabee. The authors discuss the results of a literature review and pilot study on how to prevent aggressive driving and road rage. As described in the study, road rage is criminal behavior by motorists characterized by uncontrolled anger that results in violence or threatened violence on the road. One of the goals of the study was to determine when road rage occurs most often. The days on which$69$road rage incidents occurred are presented in the following table.

Identify an important reason for grouping data.

State three of the most important guidelines in choosing the classes for grouping a quantitative data set.

For quantitative data, we examined three types of grouping: single-value grouping, limit grouping, and cut point grouping. For each type of data given, decide which of these three grouping types is usually best, Explain your answers.

a. Continuous data displayed to one or more decimal places

b. Discrete data in which there are relatively few distinct observations

We used slightly different methods for determining the "middle" of a class with limit grouping and cut point grouping. Identify the methods and the corresponding terminologies.

Explain the difference between a frequency histogram and a relative-frequency histogram.

Explain the advantages and disadvantages of frequency histograms versus frequency distributions.

Discuss the relative advantages and disadvantages of stem-and leaf diagrams versus frequency histograms.

Gas Mileage. The gas mileages, are rounded to the nearest number of miles per gallon, of all new car models.