Is the law of inertia and Newton’s first law mean exactly the same thing

yes, they both are the same thing.

step by step explanation:

both state that " an object remain to continue its state of rest or uniform motion unless an external force is applied"

the answer is true when observing or determining population size, a direct observation is use, in which each organism is counted in a population or in an area. one benefit of this measure is that you get the exact population count but it will take a long time to  determine  the  size  of a  population.