Answer: 
<u>Step-by-step explanation:</u>

Just graph is bruv. The app is called desmos
I think it is 1200 people. Because if 40% are female and there are 480 females, then do 480 x 2 and that equals 960 then half of 480 is 240 so add 960 to 240 and you get 1200 as the total amount of people there. I'm not sure if it's right, but it should be.
3/4 = 0.75 in decimal inch
Karla wants to leave 0.75 inch in her signature.
4 -0.75 = 3.25 inch needed
0.25 = 1/4
3 and 1/4 inches is needed.
Since they are the same, any change made to 1 will be the same in the other, resulting in infinite solutions.