The figure shows a scatter plot of two pulse rates, the first measurement on the horizontal axis, the second on the vertical axis. There is a fairly strong relationship (r=0.68). The line of equality is shown at 45 degrees to the two axes.
Large diamonds mark the point of the mean second pulse for first pulse = 50, 60, 70 ,80, 90, 100, 110 beats per minute. These points lie close to a straight line which has a less steep slope than the line of equality and which crosses this close to the mean point.
The two highest points are nearer the line of equlaity than the rest of the points would suggest, but there are few observations in this area.
Back to Regression towards the mean.
This page maintained by Martin Bland.
Last updated: 19 January, 2004.