x – Chart Based on Standard Deviations An x chart based on standard deviations

(instead of ranges) is made by plotting sample means with a centerline at x and control limits at x + A3s and x - A3s, where A3 is found in Table 2 and s is the mean of the sample standard deviations. Use the data in Table 1 to construct an x chart based on standard deviations.

Compare the result to the x chart based on sample ranges (as in Example 5).