Recall that frequency distribution tables help organize quantitative data with several categories, such as the number of books at different price ranges. Such frequency distribution tables can be visually represented using histograms, a graph that consists of bars of equal width drawn without gaps. The vertical axis represents the frequencies in each class, and the horizontal axis represents the class boundaries. So, what are class boundaries? The first interval in the data table shows the price ranging from 5 to 10 dollars, and the second interval offers the price range from 11 to 16. Note that the price range between 10 and 11 is missing from the table. This gap is filled in by calculating their midpoints, called the class boundaries. These class boundaries are represented on the horizontal axis and the corresponding frequencies on the vertical axis. The vertical bars, called bins, connect the class boundaries and frequency values.