1. Handling Data – Cumulative Frequency and Step Polygons Key topics : Cumulative Frequency Upper boundary, Discrete Data Continuous Data

2. Handling Data – Cumulative Frequency and Step Polygons Types of graphs covered : 1.Cumulative Frequency Step Polygons 2.Cumulative Frequency Polygons 3.Cumulative Frequency Curves

3. Cumulative Frequency and Step Polygons What is cumulative frequency?

4. Cumulative Frequency and Step Polygons What is cumulative frequency? This is where we calculate a running total of the frequencies

5. Cumulative Frequency Number of People in a Household FrequencyCumulative Frequency 233 363+6 = 9 489+8 = 17 5617+6 = 23 6323+3 = 26 7226+2 = 28 8028+0 = 28 9228+2 = 30

6. Cumulative Frequency No of letters in a crossword solution Frequency 20 30 412 59 68 78 813 94 100 115 By adding an extra column to this table, calculate the cumulative frequencies for this data.

7. Cumulative Frequency No of letters in a crossword solution FrequencyCumulative Frequency 200 300 412 5921 6829 7837 81350 9454 10054 11559

8. Cumulative Frequency Step Polygons No of letters in a crossword solution FrequencyCumulative Frequency 200 300 412 5921 6829 7837 81350 9454 10054 11559 Drawing a cumulative frequency step polygon for this data.

9. Cumulative Frequency Step Polygons No of letters in a crossword solution Frequenc y Cumulative Frequency 200 300 412 5921 6829 7837 81350 9454 10054 11559

10. Cumulative Frequency Step Polygons No of letters in a crossword solution FrequencyCumulative Frequency 200 300 412 5921 6829 7837 81350 9454 10054 11559 Plot points at upper boundary of each class

11. Cumulative Frequency Step Polygons No of letters in a crossword solution FrequencyCumulative Frequency 200 300 412 5921 6829 7837 81350 9454 10054 11559 Joins points to create steps

12. Cumulative Frequency Step Polygons No of letters in a crossword solution FrequencyCumulative Frequency 200 300 412 5921 6829 7837 81350 9454 10054 11559

13. Cumulative Frequency Polygons This graph is similar to the cumulative step polygons. Cumulative frequencies as a running total are calculated in the same way. Birth Weight (kg) 2.0- 2.5 2.5- 3.0 3.0- 3.5 3.5- 4.0 4.0- 4.5 4.5- 5.0 Frequency 12223327188 What sort of data is this?

14. Cumulative Frequency Polygons This data is continuous. Birth Weight (kg) 2.0- 2.5 2.5- 3.0 3.0- 3.5 3.5- 4.0 4.0- 4.5 4.5- 5.0 Frequency 12223327188 Cumulative Frequency 12346794112120 How would we draw the graph? What would the axes look like? Where would you plot the points?

15. Cumulative Frequency Polygons Birth Weight (kg) 2.0 - 2.5 2.5 - 3.0 3.0 - 3.5 3.5- 4.0 4.0- 4.5 4.5- 5.0 Frequency12223327188 Cumulative Frequency 12346794112120 Plot points at upper boundary of each class

16. Cumulative Frequency Polygons Birth Weight (kg) 2.0 - 2.5 2.5 - 3.0 3.0 - 3.5 3.5 - 4.0 4.0 - 4.5 4.5 - 5.0 Frequency12223327188 Cumulativ e Frequency 12346794112120 Plot points at upper boundary of each class

17. Cumulative Frequency Polygons Birth Weight (kg) 2.0 - 2.5 2.5 - 3.0 3.0 - 3.5 3.5 - 4.0 4.0 - 4.5 4.5 - 5.0 Frequency12223327188 Cumulative Frequency 12346794112120 Join points with straight lines. Start at lower bound of first class with cumulative frequency of 0.

18. Cumulative Frequency Polygons Birth Weight (kg) 2.0 - 2.5 2.5 - 3.0 3.0 - 3.5 3.5 - 4.0 4.0 - 4.5 4.5 - 5.0 Frequency12223327188 Cumulative Frequency 12346794112120 Don’t forget to give graph a title.