What Is a Stem and Leaf Plot?
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The leaves are displayed to the right of the
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Hi, I'm Scott for About.com and today I'm going to explain a stem and leaf plot.

What a Stem and Leaf Plot Shows

The Stem and leaf plot summarizes the shape, or distribution, of a set of data and provides extra detail regarding individual values. The data is arranged by place value. The digits in the largest place are referred to as the stem and the digits in the smallest place are referred to as the leaf or leaves. The leaves are displayed to the right of the stem.

Why Are Stem and Leaf Plots Used?

Stem and leaf plots are great organizers for large amounts of information. They are usually used when there are large amounts of numbers to analyze. Series of scores on sports teams, series of temperatures or rainfall over a period of time, series of classroom test scores are examples of when Stem and Leaf Plots could be used.

Sample Stem and Leaf Plot

Now I'll show you a sample stem and leaf plot: Let's look at this data set and organize it into a stem and leaf plot. We will start with these numbers: 42, 33, 11, 46, 31, 65, 22, 16, 35, and 14. It's hard to gather information from the numbers as they are, however, if we organize them into a simple stem and leaf plot, we can easily find the mean, median, mode, determine the average, or the highest and lowest numbers.

Now, this is an example of a stem and leaf diagram. All the numbers in the previous set of data are represented in this chart. The 4 here, because it is in the leaf column on the right side, means 14. You simply put the stem digit in front of the leaf digit to get the number.

Second Example of a Stem and Leaf Plot

Now I'll show you another example of a stem and leaf plot, this chart represents test scores out of 100. Again, the stem shows the 'tens' place and the leaf shows the ones place. At a glance, one can see that 4 students got a mark in the 90s on their test out of 100. Two students received the same mark of 92. No marks were received below 50. No mark of 100 was received.

Tips for Analyzing Data on a Stem and Leaf Plot

When you count the total amount of leaves, you know how many students took the test. The information is nicely organized when a stem and leaf plot is used. Stem and leaf plots provide an 'at a glance' tool for specific information in large sets of data, otherwise one would have a long list of marks to sift through and analyze.

Use a Stem and Leaf Plot to Compare Multiple Data Sets

You may also want to use a stem and leaf plot to compare more than one set of data. To compare two sets of data, you can use a 'back to back' stem and leaf plot. For instance, if you wanted to compare the scores of two sports teams, you would use the following stem and leaf plot. The tens column is now in the middle and the ones column is to the right and left of the stem column.

You can see that the Sharks had more games with a higher score than the Tigers. The Sharks only had 2 games with a score in of 32. The Tigers had 4 games, a 30, a 33, a 37 and a 39. You can also see that the Sharks had the highest score of all -- a 59, compared to the Tigers with a 57.

Tips for Using a Stem and Leaf Plot

Stem and leaf plots allow you to easy find medians, determine totals, and determine the modes. Enter the rest of the temperatures sequentially until your stem and leaf plot contains all of the data.