Understanding X-Bar Charts
The X-Bar chart shows how the mean (or average) changes over time. This chart is used to analyze central location; that is, the center of a set of sample data. The statistic used to describe the central location is the mean.
Data for the X-Bar chart can be derived from subgroups of constant size or variable sizes.
X-Bar Chart
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The average over time |
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The Upper and Lower Warning Limits |
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The Upper and Lower Control Limits |
