Question: A major supplier of rocket motorswishes to control the number of nonconformities in a subassembly area producing fuel pumps. The inspection unit is defined as four pumps, and data from 16 samples (each of size 4) are shown in the Data File.
(a) Set up a u-control chart(average number) for nonconformities per unit.
(b) Do these data come from a controlled process? If not, assume that assignable causes can be found for all out-of-control points and calculate the revised control chart parameters.
(c) Suppose the inspection unit is redefined as eight pumps. Explain how you would determine a new sample size and revisions (if necessary) to the control limits for monitoring future productions.
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0 |
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2 |
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1 |
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5 |
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