Chapter 5.3, Problem 8E

Growth Rate Versus Weight Ecologists have studied how a population’s intrinsic exponential growth rate $r$ is related to the body weight $W$ for herbivorous mammals. In table $5.2$, $W$ is the adult weight measured in pounds, and $r$ is growth rate per year.

Animal	Weight W	r
Short-tailed vole	0.07	4.56
Norway rat	0.7	3.91
Rue deer	55	0.23
White-tailed deer	165	0.55
American elk	595	0.27
African elephant	8160	0.06

Find a formula that models $r$ as a power function of $W$, and draw a graph of this function.