What is the difference between sparse, moderate, and dense population
density? In detail

Population densities are usually defined as being either dense or sparse. Sparsely populated denotes containing few people relative to size, while densely populated denotes containing a large amount of people ralative to size

Sparse population means not many people
Moderate means more people but still not a lot
Dense means it is very populated

Answerglycogen;

Well, a and b together would be negative. b alone would also be negative.