Quality Digest, March 5, 2018

Figure 1:  The 100 Wire Length Data

  Figure 2 shows 200 data from bead board number 7.  These values have an average of 12.86

and a standard deviation statistic of 3.46.  The three intervals of the empirical rule contain,

respectively, 66 percent, 97 percent, and 100 percent of the data.

1

2

3

4

5

6

7

8

9

10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

12.86

3.46

3.46

3.46

3.46

3.46

3.46

66%

97%

100%

2.48

23.24

Figure 2:  200 Data from Bead Board No. 7

Figure 3 shows 259 batch weight data.  These values have an average of 937.0 kg and a

standard deviation statistic of 61.3 kg.  The three intervals of the empirical rule contain,

respectively, 70.3 percent, 94.6 percent, and 98.8 percent of the data.

---

Donald J. Wheeler

The Empirical Rule

www.spcpress.com/pdf/DJW328.pdf

3

March 2018

750

800

850

900

950

1000

1050

1100

1150

937

61.3

61.3

61.3

61.3

61.3

61.3

70.3%

94.6%

98.8%

753

1121