Chapter 12: EWMA signals and control limits for the concentration
data in Table 12.6. Smoothing constant lambda = 0.2, starting
value EWMA0  = 50.035, and standard deviation s = 1.923. 

Col 1: Sample number.
Col 2: xi.
Col 3: EWMAi.
Col 4: Lower Control Limit.
Col 5: Upper Control Limit.

 1    49.3   49.888     48.88  51.19
 2    51.1   50.130     48.56  51.51
 3    47.7   49.644     48.38  51.69
 4    46.9   49.095     48.28  51.79
 5    48.5   48.976     48.22  51.85
 6    48.4   48.861     48.18  51.89
 7    50.1   49.109     48.15  51.92
 8    48.2   48.927     48.14  51.93
 9    48.2   48.782     48.13  51.94
10    52.2   49.465     48.12  51.95
11    53.7   50.312     48.12  51.95
12    49.9   50.230     48.12  51.95
13    51.3   50.444     48.11  51.96
14    51.0   50.555     48.11  51.96
15    52.0   50.844     48.11  51.96
16    48.7   50.415     48.11  51.96
17    50.6   50.452     48.11  51.96
18    48.2   50.002     48.11  51.96
19    53.0   50.601     48.11  51.96
20    51.7   50.821     48.11  51.96
21    44.9   49.637     48.11  51.96
22    49.3   49.570     48.11  51.96
23    46.7   48.996     48.11  51.96
24    46.8   48.557     48.11  51.96
25    49.6   48.765     48.11  51.96
26    47.8   48.572     48.11  51.96
27    42.1   47.278     48.11  51.96  
28    46.7   47.162     48.11  51.96
29    46.4   47.010     48.11  51.96
30    47.2   47.048     48.11  51.96