Question

if the age of a tree was predicted to be 800 years old using the regression equation y equals 4.39 x - 6.77 what is the diameter have to be ? this is my 5th time asking a Tudor it does not seem like no one knows how to answer this question

Answer 1

We can use the equation:

$age=\text{circumference}+\text{growth rate}$

Age is given as 800

Circumference is 2*pi*r

Growth rate is the rate of change of growth of the tree. We can find this by looking at the linear equation.

The equation is:

y = 4.39x - 6.77

Matching with y = mx + b, we can say:

m = 4.39 [m is the rate of change. So, this is the growth rate]

Now, we substitute into equation to solve for r:

$\begin{gathered} 800=2\pi r+4.39 \\ 800-4.39=2\pi r \\ 795.61=2\pi r \\ r=\frac{795.61}{2\pi} \\ r=1249.74 \end{gathered}$

Diameter is double this radius. So,

Diameter = 1249.74 * 2 = 2499.48

Diameter = 2499.48