Measuring tree height is not an easy task. How well would trunk diameter predict
ID: 3208396 • Letter: M
Question
Measuring tree height is not an easy task. How well would trunk diameter predict tree height? A survey of 958 live trees in an old-growth forest in Canada provides us with the following information: The mean tree height is 12.6 m, with standard deviation 10 m; the mean diameter is 22.2 cm, with standard deviation 13.4 cm. The correlation between the height and diameter is 0.93.
How much does tree height increase on average for each additional centimeter of diameter? Round your answer to 2 decimal places.
Explanation / Answer
Let,
y = tree height
x = diameter
We are given
r = 0.93
Sx = 13.4
Sy = 10
The slope formula ( b ) = r * ( Sy/Sx )
= 0.93 * ( 10 / 13.4 )
= 0.69
Answer: 0.69 cm three height increases on average for each additional centimeter of diameter.