#### Answer

a. $L=\frac{1890}{R}$
b. $24.9\ yrs$. not an exact model, but a very good one.
c. $70\ yrs$

#### Work Step by Step

a. Based on the given conditions, we have $L=\frac{k}{R}$ where $k$ is a constant. Using the data from horses, we have $30=\frac{k}{63}$, which gives $k=1890$, thus $L=\frac{1890}{R}$
b. Using the above equation for lions with $R=76$, we have $L=\frac{1890}{76}\approx24.9\ yrs$. This value is close to $25$ years given in the bar graph; thus the equation in part-(a) is not an exact model, but a very good one.
c. For elephants, $R=27$, we have $L=\frac{1890}{27}=70\ yrs$