A dot represents one observation; stacked dots show frequency. A stem-and-leaf diagram preserves every original value while arranging the data in order. Give a key so a stem and leaf have an unambiguous value and unit. Example The times in minutes are 12,14,14,18,21,23,23,23. Both diagrams display the same eight observations. The mode is 23 minutes because it occurs three times. The median is 18+212=19.5 minutes. Repeated leaves must remain: deleting them changes the frequencies. Dot diagrams make clusters and gaps easy to see; stem-and-leaf diagrams retain exact values. Both can become crowded for large data sets, when a grouped display is more compact.

A dot represents one observation; stacked dots show frequency. A stem-and-leaf diagram preserves every original value while arranging the data in order. Give a key so a stem and leaf have an unambiguous value and unit.

The times in minutes are \(12,14,14,18,21,23,23,23\). Both diagrams display the same eight observations.

The mode is \(23\) minutes because it occurs three times. The median is \(\dfrac{18+21}{2}=19.5\) minutes. Repeated leaves must remain: deleting them changes the frequencies.

Dot diagrams make clusters and gaps easy to see; stem-and-leaf diagrams retain exact values. Both can become crowded for large data sets, when a grouped display is more compact.

Dot diagrams and stem-and-leaf diagrams

Dot diagrams and stem-and-leaf diagrams