Stem and Leaf Plots

Below are family income figures (in thousands of dollars) for fifteen residents of a neighborhood.


17 31 25 30 21

25 28 19 32 25

32 27 21 26 21


The diagrams below are called stem-and-leaf plots (or stem plots) and represent the data above.


1 79
2 111555678
3 0123
1
* 79
2 111
* 555678
3 0123
*

  1. Where is the $26,000 income represented on each plot? Circle the digits that represent this income.

  2. If a new resident moved in who earned $14,000, how would the plots change? Reflect this change on both plots.

  3. What do the dots represent on the plot on the right?

  1. Which plot is more useful? Why?

  1. Why do you think they are called stem and leaf plots? What are the stems and what are the leaves?

  1. What might a stem-and-leaf plot be used for?

The diagram below is a rough draft of the stem-and-leaf plot from the previous page.

1 79
2 515857161
3 1022
  1. Why is this not a final draft?

  1. There is an error in the final drafts. What is it?

  1. Why is it not always practical to create a final draft on the first try?

  1. When are stem plots impractical?

The data below represents the number of beats in 14 songs.

682 647 709 855 775

813 602 725 789 913

822 862 675 820

  1. How might a stem plot be created for this data? What problems does this present that we haven't yet observed?