The center line for the range chart is always greater than the center line for the X-bar chart because the ranges are always greater than the average.

Question

Quizplus · Accepted Answer

The center line for the range chart and the X-bar chart are calculated based on different formulas. The center line for the range chart is calculated using the average range, while the center line for the X-bar chart is calculated using the process mean. It is possible for the center line of the range chart to be less than the center line of the X-bar chart if the process is consistent and the ranges are small. Therefore, the statement is false.

The Center Line for the Range Chart Is Always Greater