Bar Chart

The Bar Chart shows the laboratory mean for 13 months plotted against one of the following:

• Cumulative mean (if no fixed mean is specified)
  The Bar Chart is overlaid onto the cumulative mean ±3SD range. The cumulative mean determines the scale of the Y-axis (mean ±3SD).
• Fixed mean (if a fixed mean is specified)
  The Bar Chart is overlaid onto the fixed mean ±3SD range specified for the test. The fixed mean determines the scale of the Y-axis (mean ±3SD).

The Bar Chart also shows the SD, CV, and number of points for each monthly mean.

Tip: The Bar Chart plots monthly means against a ±3SD range. Therefore, the Bar Chart is helpful to visualize long-term shifts and trends.