X Median R Chart Formulas
The XMedianR Chart works just like the XbarR chart except that it uses the median instead of the average as a measure of central tendency.
Here are the XMedianR Chart formulas used in QI Macros for both the Range and Median charts.
Range Chart Formula
X Median Chart Formula
n = number of samples in a subgroup
k = number of subgroups used to determine the average median and range
Conforms with AIAG SPC 2nd Edition
Process: Calculate, plot, and evaluate the range chart first. If it is "out of control," so is the process. If the range chart looks okay, then calculate, plot, and evaluate the X Chart.
Note: There are no known calculations for constants in an XMedianR Chart where n > 100
Other Resources
- Create a XMedianR Chart in Excel using QI Macros
- View all Six Sigma Charts and Tools in QI Macros
- Other Control Chart Formulas
The XMedianR Chart is just one of the tools included in the QI Macros for Excel SPC Software for Excel.
Why Choose QI Macros Over Other Control Chart Software?
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- Only $329 USD - less with quantity discounts
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- Works right in Excel
- Create a chart in seconds
- Easy to customize & share charts
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