Final answer:
The model representing the female population F from 1990 through 2020 is derived by subtracting the known male population from the total population. The student's question does not provide these equations, thus one cannot definitively select an answer without them.
Step-by-step explanation:
The student has asked what model represents the female population F from 1990 through 2020 given certain equations. To answer this, we would need the equations for the total population and the male population, which are not provided. However, when determining such a model, one would subtract the male population from the total population to get the female population. With equations for total population (P) and male population (M), you would use the following formula:
F = P - M
Once you have the correct values for P and M, you can apply them to the formula and select the appropriate model that matches the result. Without the explicit equations for total and male populations, we cannot definitively choose one of the provided answers a, b, c, or d.