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

4. 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

5. Frequency Polygon for High Temperatures

6. Frequency Table for MPG of SUVs
Class
Class boundaries
Class Midpoint
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. Cumulative Frequency for MPG of SUVs
 Cumulative Frequency
 less than 11.5
 less than 12.5
 less than 13.5
 less than 14.5
 less than 15.5
 less than 16.5
 less than 17.5
 less than 18.5
 less than 19.5 :

11. Ogive for MPG of SUVs

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