The data in the accompanying table represents the percentage of workers who are members of a union for each U.S. state and the District of Columbia (AARP Bulletin, September 2009).

a. Construct a histogram of these data using class intervals of 0 to 5, 5 to 10, 10 to 15, 15 to 20, and 20 to 25.

b. Construct a dotplot of these data. Comment on the interesting features of the plot.

c. For this data set, which is a more informative graphical display—the dotplot from Part

(b) or the histogram constructed in Part (a)? Explain.

d. Construct a histogram using about twice as many class intervals as the histogram in Part (a). Use