A sample of five units is taken from a process every half hour. It is known that the process standard deviation is in control with σ = 2.0. The x values for the last 20 samples are shown in Table 10E.7. Specifications on the product are 40 ± 8.
(a) Set up a modified control chart on this process. Use three-sigma limits on the chart and assume that the largest fraction nonconforming that is tolerable is 0.1%
3-sigma limits:
(b) Reconstruct the chart in part (a) using two-sigma limits. Is there any difference in the analysis of the data?
(c) Suppose that if the true process fraction nonconforming is 5%, we would like to detect this condition with probability 0.95. Construct the corresponding acceptance control chart.

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