How Do I Use This Activity?

This activity allows the user to explore the concepts of mean, median and mode by adding/removing blocks to an axis with a given range.

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Controls and Output

• At the center and top of the activity is an axis where the user can click to add blue blocks. Simply by clicking above the axis the user can place the blocks exactly where he/she wants.
  

• When the user adds blocks little pointers should appear which indicate the respective piece of statistical information (mean, median, and mode). Note how the pointers move as you add blocks. In what cases will you get multiple pointers for mode?
  

• By clicking the appropriate radio button below the words When I click:, the user can change whether the blocks are added or removed from the column.
  

• By clicking the Increase Range or Decrease Range button the user can extend or shorten the length of the x-axis.
  

• The user can change the interval of the range by altering the X-Range Starts At value and then clicking the Set button. If the user wants to reset the entire program, he/she can click Reset.
  

• To see the statistical information in text, click the Show Stats button. The statistics panel (shown below) will appear at the bottom of the applet. When the statistics panel is visible, the Show Stats button will change to the Hide Stats. Click that button to hide the statistics panel again.
  

• The user can also enter data to be plotted by typing it in the text area in the middle of the applet. Each number should be an integer and should be separated by a comma, a space, or by pressing the enter key. Type the data you want to use, and then click Update Graph to plot your data. Click Clear to clear all the data from the text area.