Chart Preparation Exercise (8)

These two means, are used as the centre lines for each of the two graphs on the chart. The first one, () is the centre line for the X graph (the top graph), and the second one () is the centre line for the moving range graph (the bottom one).

You should now add these two lines to your printed chart. Note that throughout this course, we use colour to identify the different lines on a chart:

• The upper control limit is drawn in red
• The centre line (the mean) is drawin in blue
• The lower control limit is drawd in black

However, when working in black and white only, it is conventional to draw the control limits as solid lines and the centre line as a dashed line.

Check your chart against the example version, and if necessary, correct any errors before moving on.