## Two-Sided Stem-and-Leaf Plots

### Topic

Number of hours boys and girls spend gaming

### Vocabulary

- Two-Sided Stem-and-Leaf Plots
- Stem-and-Leaf Plots
- Data distribution
- Mean
- Median
- Mode

### Student Exploration

#### How does the number of hours that boys and girls spend gaming compare? How can you use a Two-Sided Stem-and-Leaf Plot to compare the hours?

When you imagine the average gamer (video game player) you probably envision a boy. However 2 out 5 gamers are female! In addition, one-third of gamers are women over the age of eighteen, according to http://www.grabstats.com/statcategorymain.asp?StatCatID=13. Check out the following collection of images representing different gaming stats.

Source: Online Education

Survey 30 of your gamer friends, asking them the average number of hours they spend gaming each week. Of the 30 people you survey, 15 need to be boys and 15 need to be girls. Then present your survey results in a two-sided stem-and-leaf plot!

- Once you have graphed your data, what do you notice? How does the number of hours that boys and girls spend gaming compare?

Scan and upload your two-sided stem-and-leaf plot to CK-12’s website to share with other students!

### Extension Investigation

Need help graphing?

- Split up the data into two groups, one for girls and one for boys.
- Make a two-sided stem-and-leaf plot off one “stem.” Your stem needs to be arranged vertically from the tens digit of your smallest value through the tens digit of your largest value (this might be a hundreds digit if your friends are serious gamers).
- After you set up the stem, then make the leaves! Write the leaves for the girls on one side and the boys on another side. The leaves need to be written out horizontally off of the stem.
- For more in-depth instructions revisit the “read” tab for “Stem-and-Leaf Plots.”

Answer the follow-up questions for your two-sided stem-and-leaf plot.

- Describe the distribution of the data for the number of hours that girls spend gaming.
- Describe the distribution of the data for the number of hours that boys spend gaming.
- How does the number of hours that boys and girls spend gaming compare? How does your graph show this? Explain.
- What are the advantages of displaying this data in a two-sided stem-and-leaf plot? Explain.
- Which graph would provide a better graphic representation of this data? Explain why.
- What is the mean number of hours boys spend gaming? What is the mean number of hours boys spend gaming?
- What is the median number of hours boys spend gaming? What is the median number of hours boys spend gaming?
- What is the mode number of hours boys spend gaming? What is the mode number of hours boys spend gaming?
- Which measure of central tendency (mean, median or mode) is the most useful in analyzing this data? Explain why.

Complete another two-sided stem-and-leaf plot where you compare two other gaming stats for your friends. Here are a couple of examples:

- Compare the number of hours that students with different grade point averages spend gaming.
- Compare the number of hours that gamers of different ages spend gaming.
- Compare the number of hours that gamers of different weights spend gaming.

What do you notice?

Scan and upload your two-sided stem-and-leaf plot to CK-12’s website to share with other students!

### Resources Cited

http://www.grabstats.com/statcategorymain.asp?StatCatID=13.

http://www.onlineeducation.net/videogame

### Connections to other CK-12 Subject Areas

- Stem-and-Leaf Plots
- Measures of Central Tendency and Dispersion
- Mean
- Median
- Mode