The problem says that there's a proportion between females and males, and this proportion is 3:2, for 3 females there are 2 males.
That means that if we divide the people into 5 equal parts, 3 parts will be female and 2 parts will be male.
Using that logic, let's divide the county people into 5 equal parts
[tex]\frac{1760}{5}=352[/tex]Then each part has 352 people. As we said, 3 parts will be female, then
[tex]\begin{gathered} f=352\cdot3 \\ \\ f=1056 \end{gathered}[/tex]Therefore, there are 1056 females.
And the males will be 2 parts, then
[tex]\begin{gathered} m=352\cdot2 \\ \\ m=704 \end{gathered}[/tex]We can also check that the males + females must be all the population:
[tex]\begin{gathered} p=m+f \\ p=704+1056 \\ p=1760 \end{gathered}[/tex]Again, there are 1056 females in the county