A control chart consists of several parts. It has two control limits and an average line. The bottom dashed line is called the lower control limit (LCL). The solid middle line is the average of the ...

As an illustration, the calculation of control limits looks like: (Note: The hat over the sigma symbol indicates that this is ...

Will Kenton is an expert on the economy and investing laws and regulations. He previously held senior editorial roles at Investopedia and Kapitall Wire and holds a MA in Economics from The New School ...