Question 12: Would we get a different P value if we carried out the regression of height on head circumference?
We get a different line, but the P value is the same.
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.