- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

#### Presentation Transcript

**2. **Chapters 2 & 3 (Part A)Descriptive Statistics:Tabular and Graphical Presentations Summarizing Qualitative Data
Summarizing Quantitative Data

**3. **Summarizing Qualitative Data Frequency Distribution
Relative Frequency Distribution
Percent Frequency Distribution
Bar Graph
Pie Chart

**4. **Construction of a Frequency Distribution

**6. **Example: Marada Inn Guests staying at Marada Inn were
asked to rate the quality of their
accommodations as being excellent,
above average, average, below average, or
poor. The ratings provided by a sample of 20 guests are:

**9. **Percent Frequency Distribution

**11. **Bar Graph

**13. **Pie Chart

**16. **Summarizing Quantitative Data Frequency Distribution
Relative Frequency and Percent Frequency Distributions
Dot Plot
Histogram
Cumulative Distributions
Ogive

**17. **1- Determine range
2- Select number of classes
Usually between 5 and 20 inclusive
3- Compute class intervals (width)
4- Determine class boundaries (limits)
5- Compute class midpoints
6- Count observations & assign to classes Frequency Distribution TableSteps

**18. **Example: Hudson Auto Repair

**20. **Frequency Distribution Guidelines for Selecting Number of Classes

**21. **Frequency Distribution (Continued) Guidelines for Selecting Width of Classes

**22. **Example: Frequency Distribution For Hudson Auto Repair, if we choose six classes:

**23. **Solution Using SWStat+ After putting your data into Excel, then create Data Area:

**24. **SwStat Statistics Tabulations and Histograms
Note that here we are using 10 classes—you can use 6 classes if you would like to do so.
Solution Using SWStat (cont.)

**25. **Results: Solution Using SWStat (cont.)

**26. **Relative Frequency andPercent Frequency Distributions

**28. **Dot Plot One of the simplest graphical summaries of data is a dot plot.
A horizontal axis shows the range of data values.
Then each data value is represented by a dot placed above the axis.

**29. **Dot Plot

**30. **Histogram

**31. **Histogram

**32. **Symmetric
Left tail is the mirror image of the right tail
Example: heights and weights of people Histogram (Continued)

**33. **Moderately Skewed Left
A longer tail to the left
Example: exam scores Histogram (Continued)

**34. **Moderately Right Skewed
A Longer tail to the right
Example: housing values Histogram (Continued)

**35. **Highly Skewed Right
A very long tail to the right
Example: executive salaries Histogram (Continued)

**37. **Cumulative Distributions Example: Hudson Auto Repair

**41. **Frequency Distribution TableAnother Example

**42. **Frequency Distribution TableExample (Continued)

**45. **Relative Frequency & % Distribution TablesExample (Continued) The number of classes is usually between 5 and 15. Only 3 are used here for illustration purposes.The number of classes is usually between 5 and 15. Only 3 are used here for illustration purposes.

**46. **Cumulative Percentage Distribution TableExample (Continued) The number of classes is usually between 5 and 15. Only 3 are used here for illustration purposes.The number of classes is usually between 5 and 15. Only 3 are used here for illustration purposes.

**47. **End of Chapters 2 & 3, Part A