Similarities:

• Dotplots and stem-and-leaf displays both show every data value.

Differences:

• Stem-and-leaf displays group the data with the same stem, whereas dotplots only group the data with identical values.

Explanation:

• Dotplots: Each data point is represented by a dot plotted above a number line. If multiple data points have the same value, they are stacked vertically, but each value is still visible.
• Stem-and-leaf displays: These group data by the "stem" (e.g., the leading digits) and show individual values as "leaves" (e.g., the trailing digits). This method allows for easy visualization of the distribution while preserving each data point's value.

Relative Questions:

1. What types of data sets are best represented by dotplots?
2. How can you interpret skewness from a dotplot?
3. What are the advantages of using a stem-and-leaf display over a dotplot?
4. How do you create a stem-and-leaf display for a set of decimal numbers?
5. Can a stem-and-leaf display be used for large data sets? Why or why not?
6. What other graphical displays are similar to dotplots?
7. How would you modify a dotplot to better show changes over time?
8. How do you interpret outliers in a stem-and-leaf display?

Tip:

When comparing two data sets, dotplots can be especially useful for visually assessing differences in distribution, while stem-and-leaf displays are excellent for highlighting individual data points within a group.