So far, you’ve learned how to display data graphically. Now, we will use the graphs to analyze the data and find measures of center and variability. Graphical displays of data can also be helpful when comparing two or more sets of data.
Example:
The table shows the number of wins of two middle school basketball teams for the past ten years.
| Lakeview MS | 24 | 26 | 24 | 10 | 8 | 11 | 8 | 13 | 16 | 10 |
|---|---|---|---|---|---|---|---|---|---|---|
| Mountainside MS | 14 | 11 | 11 | 16 | 14 | 9 | 18 | 11 | 16 | 15 |
- Which team had a greater range of wins? (Write your answers down. You’ll be checking them later.)
- What is the mean number of wins for each team?
To be able to compare the data easily, let’s arrange the data above into stem-and-leaf plots.
Lakeview MS
0 | 8 8
1 | 0 0 1 3 6
2 | 4 4 6
Mountainside MS
0 | 9
1 | 1 1 1 4 4 5 6 6 8
3. Which middle school has a more consistent number of wins?
4. Find the median number of wins for each team.
(source)