Exercise: Head circumference and height, answer 12

Question 12: Would we get a different P value if we carried out the regression of height on head circumference?

Suggested answer

We get a different line, but the P value is the same.

See detailed description at d. d

The regression equation is:

        height = 853 + 1.43 head circumference

This is quite different from the equation

        head circumference = 372 + 0.114 height

which we had earlier. This can be rewritten as

        (head circumference – 372)/0.114 = height


        height = –372/0.114 + (1/0.114) head circumference = –3263 + 8.77 head circumference

which is a much steeper line, as shown on the scatter diagram above.

The P value is <0.001, exactly as we had earlier.

Back to Exercise: Head circumference and height.

To IAPT index.

To Martin Bland's M.Sc. index.

To Martin Bland's home page.

This page maintained by Martin Bland.
Last updated: 2 March, 2009.

Back to top.