1. Frequency Polygons and Ogives
Chapter 2.2
Frequency Polygons and Ogives

2. The frequency polygon
The frequency polygon is a graph that displays the data by using lines that connect point plotted for the frequencies at the midpoints of the classes. The frequencies are represented by the heights of the points

3. Steps for creating a frequency polygon
Find the midpoints of each class.
Draw and label the x and y axes. Label the x- axis with the midpoints of each class, the y- axis as frequency
Plot the points, x values = midpoints, y values = frequency
Connect adjacent point with line segments. Connect to x-axis at beginning and end of graph

4. Record High Temperatures for Each State
Class Limits
Class boundaries
Class Midpoint
Frequency 2 8 18 13 7 1

5. Frequency Polygon for High Temperatures

6. Frequency Table for MPG of SUVs
Class
Class boundaries
Class Midpoint
Frequency
Cumulative Frequency 12 6 13 1 14 3 15 16 8 17 2 18 19

7. Frequency Polygon for MPG of SUVs

8. Ogive
The ogive is a graph that represents the cumulative frequencies for the classes in a frequency distribution.

9. Steps for creating an Ogive
Find the cumulative frequency for each class
Draw the x and y axes. Label x-axis with class boundaries, y-axis cumulative frequencies
Plot the cumulative frequency
Connect adjacent points with line segments

10. Ogive for MPG of SUVs

11. Real Estate Activity Creating Frequency Distributions Histograms
Frequency Polygons
And Ogives