Question

Assume you have collected data pairs (x, y) on a certain variety of tree. x is

the number of weeks since the tree was planted and yis the height of the tree
in inches. A plot of the data points with the best-fit line is given below. What is
the numerical value of the height as predicted by the best-fit line for an age of
120 weeks?

Answer 1

140 is the real asnwer :)

Answer 2

`y = 120\,in`

Explanation:

The points show a high postive correlation with a linear model, whose slope is constant:

`m = (\Delta y)/(\Delta x)`

`m = (20\,in)/(20\,weeks)`

`m = 1\,(in)/(weeks)`

The numerical value predicted by the fit line is:

`y = 20\,in + \left(1\,(in)/(weeks) \right)\cdot (120\,weeks)`

`y = 120\,in`