A report from Texas Transportation Institute (Texas A&M University System, 2005) on congestion reduction strategies looked into the extra travel time (due to traffic congestion) for commute travel per traveler per year in hours for different urban areas. Below are the data for urban areas that had a population of over 3 million for the year 2002.
a. Compute the mean and median values for extra travel hours. Based on the values of the mean and median, is the distribution of extra travel hours likely to be approximately symmetric, positively skewed, or negatively skewed?
b. Construct a boxplot that shows outliers for these data and comment on any interesting features of the plot.