Chapter 2 Organizing data

1. Chapter 2 Organizing data This is RAW DATA

2. Three types of Frequency distributions: • Categorical Frequency distributions (Qualitative) • Grouped Frequency distributions (Quantitative with large spread) • Ungrouped frequency distributions(Quantitative with small spread) • ******for ungrouped the interval width is = 1. **********

3. Example one: Categorical

4. Rules for a grouped frequency distribution • 1. There should be between 5 and 20 classes • 2. Preferable for class width to be an odd number • 3. classes must be mutually exclusive • 4. Classes must be continuous • 5. Classes must be exhaustive • 6. Classes must be equal in width ***Class width (interval width) = (Max – Min)/ number of classes***

5. Practice: Are the frequency distributions legit?

6. Example two: grouped frequency distribution

7. Cumulative distribution (will be given by megastat) • --is a distribution that shows the number of data values less than or equal to specific value (usually an upper boundary)

8. Example 3 ungrouped frequency distribution

9. Practice

10. Work with a partner and do the following: age 5214, 15, 19 HW: Page 51 1-8,

11. Charts and graphs • Histograms • Frequency polygons • ogives

15. Relative frequency graphs • The y axis is proportion rather than frequencies. (percentages)

16. Shape: Symmetric, Left skewed and right skewed

18. Other types of graphs Bar graph Pareto chart Time series Pie graph Dot plot Stem and leaf plot Box and whiskers

19. Bar graph and pareto chart

24. Misleading graphs

25. Misleading cont’d

26. Homework • Page 101-103 1-26 all • Chapter 2 quiz next class—using homework, notes and megastat.