Moving Range Chart
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Stat > Control Charts > Variables Charts for Individuals > Moving Range

A moving range chart is a chart of moving ranges - ranges calculated from artificial subgroups created from successive observations. You can use moving range charts to track the process variation and detect the presence of special causes when your sample size is 1.

By default, Moving Range chart estimates the process variation, s, with MR / d2, the average of the moving range divided by an unbiasing constant. The moving range is of length 2, since consecutive values have the greatest chance of being alike. You can also estimate s using the median of the moving range, change the length of the moving range, or enter a historical value for s.

For more information, see Control Charts Overview and Variables Control Charts for Individuals Overview.

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Variables: Choose one or more columns. Minitab calculates the moving ranges of length K for all nonmissing data and plots them on the chart. K is determined by the moving range span specified in Length of moving range in MR Options > Estimate.

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