The file DJIA Monthly Close.xlsx contains monthly values of the Dow Jones Industrial Average from 1950 through 2011. It also contains the percentage changes from month to month. (This file will be used for an example later in this chapter.) Create a new column for recoding the percentage changes into six categories: Large negative (<−3%), Medium negative (<−1%, ⩾−3%), Small negative (<0%, ⩾−1%), Small positive (<1%, ⩾0%), Medium positive (<3%, ⩾1%), and Large positive (⩾3%). Then create a column chart of the counts of this categorical variable. Comment on its shape.