The smallest value is one, and the largest value is 11.5. The first quartile is two, the median is seven, and the third quartile is nine. In those cases, the whiskers are not extending to the minimum and maximum values. You may encounter box-and-whisker plots that have dots marking outlier values. The box plot gives a good, quick picture of the data.
The median or second quartile can be between the first and third quartiles, or it can be one, or the other, or both. The “whiskers” extend from the ends of the box to the smallest and largest data values. Approximately the middle 50 percent of the data fall inside the box. The first quartile marks one end of the box and the third quartile marks the other end of the box. The smallest and largest data values label the endpoints of the axis. To construct a box plot, use a horizontal or vertical number line and a rectangular box. We use these values to compare how close other data values are to them. A box plot is constructed from five values: the minimum value, the first quartile, the median, the third quartile, and the maximum value. They also show how far the extreme values are from most of the data.
Box plots (also called box-and-whisker plots or box-whisker plots) give a good graphical image of the concentration of the data.
