Answer:
The relationship between the circulation (heart rate or blood flow) of two mammals and their body masses is typically described by an allometric scaling law known as Kleiber's law.
According to Kleiber's law, the relationship between an animal's metabolic rate and its body mass follows a power law. In this case, we can apply this scaling law to the circulation of mammals, assuming that it is proportional to their metabolic rate.
Kleiber's law states that metabolic rate scales with body mass (M) to the power of 3/4. Therefore, if one mammal has a circulation (metabolic rate) that is 4 times that of another mammal, we can express their body mass relationship as follows:
(M1 / M2)^(3/4) = 4
Taking the fourth root of both sides:
M1 / M2 = 4^(4/3)
Simplifying further:
M1 / M2 ≈ 2.5198
Therefore, the body mass of the mammal with a circulation 4 times that of the other mammal would be approximately 2.5198 times larger.