Estimated sigma = average range/d2 ... looking at the data from your processes. Understanding how your Process Sigma relates ...

A control chart consists of several parts. It has two control limits and an average line. The bottom dashed line is called ...

For each of these, you would select the range of cells you want to use after the parentheses. For example, you might enter =VAR.S(B12:B32) to find the variance for the data in cells B12 to B32 ...