Individuals and moving range chart formulas
The most common (and recommended) method of computing control limits for an individuals chart based on 3
standard deviations 
is:
Individuals (X)
Upper control limit: |
Lower control limit: |
Moving Range
Upper control limit:
|
Lower control limit:
|
Tabular values for X and range charts |
||||
Subgroup Size |
E2 |
D4 |
||
1 |
2.660 |
3.268 |
||
2 |
2.660 |
3.268 |
||
3 |
1.772 |
2.574 |
||
4 |
1.457 |
2.282 |
||
5 |
1.290 |
2.114 |
||
6 |
1.184 |
2.004 |
||
7 |
1.109 |
1.924 |
||
8 |
1.054 |
1.864 |
||
9 |
1.010 |
1.816 |
||
10 |
0.975 |
1.777 |
||
