How to Make a Stem Plot
Question
Stem plots are useful ways to organize and visualize
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Hi, I'm Ben Owens, math educator at the University of North Texas. I'm here for About.com to show you how to make a stem plot.A Stem Plot (or Stem-and-Leaf Plot) is simply a way of organizing data to make it easier to analyze.   Say you have a bunch of data, different numbers -- exam results for example. Typically data are all "jumbled up" when in their raw form.  A stem and leaf plot is one way to help “unscramble” this mess!   First we have to look at the data and find the highest and lowest value.   If possible, its also useful to order the data from least to greatest. (Depending on the amount of numbers you have, this might take a while.)  Then we must determine what we want to be the stem and what we want to be the leaf. In this case, we are going to make the first number (the tens digits) the stem, and the second number (the ones digits) the leaves.  Making a stemplot basically involves rewriting the numbers. We first make the stem by listing the numbers from the tens place in a column from least to greatest. We put all of those right under each other, like so. This is our stem.  Now we draw a vertical line to separate the stem from the leaves. Then, we move on to the leaves. We start with the number 3, we only have one number in the thirties, and the leaf is 5. So, let's put the number 5 after the number 3. Then, we move on to the number four, we have 3 of those in our exam results: 2 (...) 6 (...) and 8 (...). So let's put those behind our stem number four. We continue doing this, until we're at the final stem number, in our case 9. And that's it: your stem-and-leaf plot is finished.Stem plots are useful ways to organize and visualize how relatively small data sets are distributed. In our case, the teacher can easily see how well the class did on this exam.  It is also useful in determining the mode of a data set! One cool fact about a stem-and-leaf plot is that if you turn it on its side it becomes a histogram! As you can see, math isn't all that difficult!