A control chart constructed using a mean is known as what?

A control chart constructed using a mean is referred to as an x̄ chart, which tracks the average of a sample of measurements over time. This type of chart is particularly useful in monitoring processes to ensure that they remain stable and under control. The x̄ chart allows for the visualization of shifts or trends in the average level of a process, providing critical information about its performance.

Using the mean as the basis for monitoring is beneficial because it summarizes a set of data points, reducing their complexity and allowing for easy interpretation of the process behavior over time. This enables quality control professionals to identify variations that may signal issues requiring investigation, thus supporting continuous improvement efforts.

In contrast, the R-chart focuses on the variability within the samples rather than their means, the p-chart is suited for tracking the proportion of defective items in quality control, and the s-chart monitors the standard deviation of the process. Each of these charts serves specific purposes in statistical quality control, but when the focus is on averaging data, the x̄ chart is the appropriate choice.