As we saw in the previous section, 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 the approximate change in life span under the following conditions. Then calculate the actual change in life span and compare.

(a) The brain mass stays at 7.35 g, while the body mass goes from 150 g to 151 g.
(b) The body mass stays at 68,700 g, while the brain mass goes from 14,100 g to 14,101 g.