7.2. Bar Graphs, Histograms and Stem-and-Leaf Plots http://www.ck12.org
The stem-and-leaf plot can be interpreted very easily. By very quickly looking at stem 6, you see that 4 males spent
60 ’some dollars’ on Prom night. By counting the number of leaves, you know that 40 males responded to the
question concerning how much money they spent on prom night. The smallest and largest data values are known
by looking and the first and last stem-and-leaf. The stem-and-leaf is ’quick look’ chart that can quickly provide
information from the data. This also serves as an easy method for sorting numbers manually.
Example 2:The women from the senior citizen’s complex bowl everyday of the month. Lizzie had never bowled
before and was enjoying this new found pastime. She decided to keep track of her best score of the day for the month
of September. Here are the scores that she recorded:
77 80 82 68 65 59 61
57 50 62 61 70 69 64
67 70 62 65 65 73 76
87 80 82 83 79 79 77
80 71
In order for Lizzie to see how well she is doing, create a stem-and-leaf plot of her scores.
TABLE7.8: Lizzie’s Bowling Scores
Stem Leaf
5 0,7,9,
6 1, 1, 2, 2, 4, 5, 5, 5, 7, 8, 9
7 0, 0, 1, 3, 6, 7, 7, 9, 9
8 0, 0, 0, 2, 2, 3, 7Let’s return to the problem that was posed at the beginning of the lesson. You are supposed to display the amount of
time your young brother or sister stayed in the water each time you went swimming. Let’s look at some options.
Solution:
TABLE7.9: Minutes in Water
Stem Leaf
1 2, 3
2 1, 7
3 3, 4, 5, 7,
4 0, 0, 1Frequency Distribution Table
TABLE7.10: Minutes in Water
Bin Frequency
[ 10 − 20 ) 2
[ 20 − 30 ) 2
[ 30 − 40 ) 4
[ 40 − 50 ) 3