Box and Whisker Plot OUTSIDE?

I walked outside today and saw a box and whisker plot on the sidewalk.

I guess being a teacher, I was immediately drawn to be critical.  The box and whiskers were perfectly symmetric.  The numbers for the extreme values and quartile cutoffs were the only thing plotted.  These values implied that a long lower tail should have existed.  I asked the teacher how this was created and she said that the students put themselves in order by the day of the month they were born.  So the box and whisker plot implied that there was a large variation from 1 to 14.5 of students who were born in the earlier days of each month.  The teacher demonstrated how to find cutoff values for the quartiles by having the students in a line.  I really liked the idea of this demonstration to help students understand the quartile splits.  I believe the graph on the ground should be compared to the same graph on an adequate scale.  Students would be able to understand how the cutoff values are created and why the scale is so important.  The teacher next to me suggested having the students line up in order of how many siblings they have, or the amount of people they have living in their house.  I would expect a long upper quartile tail in this situation as though families of 8 are much less frequent these days.


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