Question

What is the difference between an R chart and an\(\bar x\) chart?

Short answer

The key difference between an\(\bar x\) chart and an R chart is that the \(\bar x\) chart is used to monitor the change in the average value of the variable over time. In contrast, the R chart monitors the change in the range/variability of the variable over time.

Step-by-step solution

Given information

An R chart and \(\bar x\) chart are plotted to identify whether a process is under statistical control or not.

Step 2:Difference between R chart and \(\bar x\) chart

An R chart is a plot that shows the sample ranges of all the samples varied over time.

It is plotted when the individual sample size is less than 10.

It examines the variation present in the process.

An\(\bar x\)chart is a plot that shows the sample means varied over time.

It examines the central value of the process.

The main difference between the two types of control charts is that the\(\bar x\)chart is used to assess the process mean,whereas the R chart isused to assess process variability.