Graph description: Figure 9. Repeated measures of PEFR using mini Wright peak flow meter

This is a scatter diagram, showing average P E F R by the mini meter on the horizontal axis and the difference in P E F R, first mini meter measurement minus second mini meter measurement, on the vertical axis. The vertical and horizontal scales have similar sized intervals representing 100. The horizontal scale is labeled 200, 300, 400, 500, 600, 700 litres per minute. The vertical scale is labeled minus 100, minus 50, 0, 50, and 100 litres per minute.

There is one horizontal line on the graph, through zero.

The points form a horizontal cloud with the centre at about 450 horizontally and 0 vertically. The horizontal range of the cloud is from about 240 to 660 litres per minute. The vertical range of the cloud for all but one point is about minus 30 to plus 40. There is an outlier at about average = 400, difference = minus 100 litres per minute.

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This page maintained by Martin Bland.
Last updated: 29 April, 2008.