110 girls and 85 boys.
Subtract 1 from 195. Then divide by 2. 194/2 = 97. Then add 13 97+13=110. There are 110 girls.
12x - 4y = -8
y = 3x + 2
Rewrite the first equation
12x + 8 = 4y
3x + 2 = y
As you see, the first and second equation are actually the same, meaning there's an infinite number of solutions.
The Population mean is 3.3 and the Sample mean is 3.6, 3.6-3.3 is 0.3