Stem and Leaf Plot
A stem-and-leaf plot shows data arranged by place value. To make a stem-and-leaf plot:
- Arrange the data in order
- List the stems in order in the first column. Typically, the stem is all but the last digit of each data point and the leaf is the last digit.
- For each stem, record the ones digits of each data value in order from least to greatest. Write these in the second column.
A stem and leaf plot looks like this:
The numbers on the left are called the stem. The numbers on the right are the leaves. Notice the two red numbers. These numbers represent the number 25.
A frequency table is a common way to organize large amounts of data. A frequency table shows the number of times each item appears. It has a scale that includes all of the numbers in the data and an interval, which separates the scale into equal parts.
A frequency table has 3 columns: interval, tally, and frequency.
For example – Say you asked your classmates what type of pet they had. You would use a frequency table to collect the data.
You count the data and make a tally mark in the tally column. Then you total the tally marks. This helps you to see where the data falls.
A frequency table can be used to create a histogram. A histogram is another way to display data using bars that have been organized into equal intervals. A histogram has the following characteristics:
- There is no space between bars.
- All of the bars have the same width (because the intervals are all equal).
- Intervals with a frequency of 0 don’t have a bar.
A line graph compares changes over time. To draw a line graph:
- Draw and label the horizontal and vertical axes. Be sure to title the graph.
- Choose a scale and interval for the data and mark equal spaces on the vertical axis.
- Mark equal spaces on the horizontal axis and be sure to label the categories.
- Draw a dot to show the frequency in each category. Finally, draw a line to connect the dots.