Researchers have estimated the maximum life span (in years) for various species of mammals according to the formula L(E, P) = 23E^0.6P^-0.267, where E is the average brain mass and P is the average body mass (both in g). Find L for the following species. Do these values seem reasonable?

(a) Black rat, with E = 7.35 g, P = 150 g
(b) Humans, with E = 14,100 g, P = 68,700 g