1. CHAPTER 5 Fundamentals of Statistics
Quality Control
Source: Besterfield, Dale H., Quality Control.

2. Frequency Distribution Characteristics of Frequency Distribution Graphs
leptokurtic  curve is quite peaked
platykurtic  curve is flat

3. Measures of Central Tendency
Measure of central tendency
describes the central position of the data
describes how the data builds up in the center
There are three measures in common use:
average
median
mode
Focus is on “ungrouped data”

4. Measures of Central Tendency Average
“X bar”

5. Measures of Central Tendency Average
In class example problem:

6. Measures of Central Tendency Median
Ordered set 3, 4, 5, 6, 8, 8, and 10
median equals 6
Ordered set 22, 24, 24, 24, and 30
median equals 24
Ordered set of numbers 3, 4, 5, 6, 8, and 8
median equals (5 + 6)/2 = 5.5

7. Measures of Central Tendency Mode
Mode (Mo)
value that occurs with the greatest frequency
mode can be nonexistent
more that one mode
series of numbers 3, 3, 4, 5, 5, 5, and 7
mode equals 5
series of numbers 22, 23, 25, 30, 32, and 36
mode equals = ?
series of numbers 105, 105, 105, 107, 108, 109, 109, 109, 110, and 112
mode equals 105 and 109

8. Measures of Central Tendency Relationship Among the Members of Central Tendency

9. Measures of Dispersion Introduction
In class demonstration: throw chalk at the board

10. Measures of Dispersion Range
Range calculation for a quick measure of dispersion

11. Measures of Dispersion Standard Deviation
Standard deviation for an accurate measure of dispersion

12. Measures of Dispersion Standard Deviation
In class example for ungrouped data:

13. Measures of Dispersion Relationship Between the Measures of Dispersion
Comparison:

14. Other Measures Skewness
Skewness is a lack of symmetry of the data.

15. Other Measures Kurtosis
Kurtosis is the peakedness of the data.

16. Concept of a Population and a Sample
Population vs. sample notation:

17. The Normal Curve Description
Population that is quite common is called the normal curve
Gaussian distribution
symmetrical
unimodal
bell-shaped distribution
mean, median, and mode are equal

18. The Normal Curve Relationship to the Mean and Standard Deviation

19. The Normal Curve Relationship to the Mean and Standard Deviation

20. The Normal Curve Relationship to the Mean and Standard Deviation

21. The Normal Curve Applications

22. The Normal Curve Tests for Normality
How to determine if the data are normal?
Histogram - visual examination of a histogram
Skewness and Kurtosis measurements
Probability plots – linear trend on special paper
Chi-square (2) test – minimum sample size of 125 required to calculate an expected value

23. SME
Lean Automation 23 min