X-11 decomposition - X-11 decomposition is a seasonal-adjustment method that uses successive moving-average filters to separate a time series into trend-cycle, seasonal, and...
X-bar-R chart - An X-bar-R chart is a paired statistical process-control display that monitors subgroup averages and subgroup ranges over time.
X-bar-S chart - An X-bar-S chart is a paired process-control display that monitors subgroup means and subgroup standard deviations over time.
XML database - An XML database is a database designed to store, manage, and query information represented in XML, the Extensible Markup Language.