1. Assume that items produced are supposed to be normally distributed with mean 35 and standard deviation 3. To monitor this process, subgroups of size 5 are sampled. If the following represents the averages of the first 20 subgroups, does it appear that the process was in control?

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Subgroup No. X Subgroup No. X 12345 34.0 2 31.6 3 30.8 4 33.0 6789 32.2 33.0 32.6 33.8 35.0 10 35.8