graph.The next step is to calculate the value of 3 sigma (written 3s on the
calculation sheet. This value will be required in the next section when
we calculate the control limits for the graph.
Once again, the calculation uses a control chart constant (this time A2) and the mean range. These values have already been entered into the appropriate boxes below. Complete the calculation and enter the result in the box outlined in red. Because this is an intermediate result to be used in later calculations, we don't want to round it too much at this stage, so your result should be rounded to 3 decimal places. When you have done this, click the button to check your answer.