# Exponential and Logarithmic Equations : Modeling

The number of trees per acre N of a certain species is approximated by the model

N=68(10^-0.04x), 5 <_ x <_ 40 (<_ = less than or = to)

Where x is the average diameter of the trees (in inches) three feet above the ground. Use the model to approximate the average diameter of the trees in a test plot when N=21.

Â© BrainMass Inc. brainmass.com March 4, 2021, 5:48 pm ad1c9bdddfhttps://brainmass.com/math/basic-algebra/exponential-logarithmic-equations-modeling-11911

#### Solution Preview

To solve this problem, you want to know x when N=21. Thus your first step is to ...

#### Solution Summary

An exponential equation is used to model the average diameter of a group of trees.

$2.49