ANALYZING, GRAPHING AND DISPLAYING DATA Graphs are used to display data in different ways. There are many types of graphs such as, bar graphs, histograms and line graphs. • A bar graph compares data in categories and uses bars, either vertical or horizontal, to display the data. • A histogram is used to graph frequency tables. It is similar to a bar graph, but with histograms the bars touch each other where with bar graphs the bars do not touch each other. • A line graph is useful for graphing how data changes over time. With a line graph, data is plotted as points and lines are drawn to connect the points to show how the data changes. • Frequency tables and spreadsheets all display data and can be used to make histograms, bar graphs or line graphs. • A scatter plot takes the data from a table and plots it on the coordinate plane. The points on the plane represent a relationship between the data. • A stem-and-leaf plot is usually used with two digit numbers. With this type of plot, the stem is the tens place value and the leaves are the ones place value. How to use analyzing, graphing and displaying data: • When using a bar graph, histogram, and line graph, it is important that the graph starts at 0. This ensures that the data will be properly displayed. With a vertical bar graph, the categories are on the x-axis and the scale is on the y-axis. • With a line graph, the line shows how the data changes over a period of time. If the line goes up, it means the data increased. If the line goes down, it means that the data decreased. If the line is flat from one point to another, it means that the data stayed the same. © Copyright NewPath Learning. All Rights Reserved. Permission is granted for the purchaser to print copies for non-commercial educational purposes only. Visit us at www.NewPathLearning.com.
• Frequency tables are used to display intervals or categories, and how many times that interval or category is picked. The frequency table below shows the intervals of hours of sleep a group of twenty- seven people get per night. • Spreadsheets are also used to display data. A spreadsheet is very useful for displaying bank accounts and financial matters such as budgets. • A scatter plot is useful to see relationships between the data. If a scatter plot shows the data to be almost on a line, there is a strong relationship with the data. • The stem-and-leaf plot shows data based on two place values. The following data, 15, 16, 18, 22, 25, 36, 32, 31 would be shown as follows with the key being 1|3 = 13 with a stem-and-leaf plot: 1 | 5, 6, 8 2 | 2, 5 3 | 1, 2, 6 © Copyright NewPath Learning. All Rights Reserved. Permission is granted for the purchaser to print copies for non-commercial educational purposes only. Visit us at www.NewPathLearning.com.
Try This! 1. Make a bar graph for the data that shows the number of acres in national forest: Yellowstone- 2,200,000 Adirondack- 6,000,000 Glacier- 999,200 2. Make a line graph and a scatter plot for the data that shows how the price of sneakers has risen: 1970- $5.00 1980- $7.50 1990- $15.00 2000- $20.00 3. Make a histogram based on the frequency table: 4. Make a stem-and-leaf plot for the data about number of hours worked at a factory: 35, 40, 42, 38, 25, 20, 33, 28, 41, 40 © Copyright NewPath Learning. All Rights Reserved. Permission is granted for the purchaser to print copies for non-commercial educational purposes only. Visit us at www.NewPathLearning.com.