The following data represent measurements made on a process for 30 days. One measurement was made each day. Assuming that 30 measurements are enough that X ̅ → μ and s → σ, find the mean of the values, the standard deviation, and the upper and lower control limits. Plot the data points along with the statistical quantities on a chart, and determine whether the process was always in statistical control.

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Day Value Day Value Day Value 1 49.8 11 49.5 21 58.8 48.4 12 50.5 22 51.3 3 49.8 13 48.9 23 50.6 4 50.8 14 49.7 24 48.8 49.6 15 48.9 25 52.6 6. 50.2 16 48.8 26 54.2 51.7 17 48.6 27 49.3 8. 50.5 18 48.1 28 47.9 9. 47.7 19 53.8 29 51.3 10 50.3 20 49.6 30 49.3