Mean versus median
The applet below is designed to allow one to investigate interactively
the mean and the median as measures of the center of a data set.
Points can be added to the plot by clicking the mouse above the
horizontal axis. The mean of the points is
shown as a green arrow, and the median is
shown as a red arrow. If the two values are the same, then a single
yellow arrow is displayed. Numeric values for the mean and median are
shown above the plot. Points on the plot can be removed by clicking
on the point and then dragging the point into the trash can. All of
the points on the plot can be removed by simply clicking inside the
trash can. The range of values for the horizontal axis can be
specified by inputing lower and upper limits and then clicking the
Update button. Things to try with the applet: