could you help me with this?

Answer:
[tex]\huge\boxed{\text{1.}}[/tex]
She did the ratio of GIRLS to BOYS, while the question asked for the ratio of BOYS to GIRLS. Therefore she swapped her proportion and data can get mixed up when you swap them. It's always important to keep the proportion in the same way that it was asked.
[tex]\huge\boxed{2.}[/tex]
[tex]\text{15 to 13}[/tex]
[tex]\text{15:13}[/tex]
[tex]\frac{15}{13}[/tex]
Step-by-step explanation:
We have 13 girls and 15 boys in the class. Therefore we can represent this as [tex]\frac{g}{b} = \frac{13}{15}[/tex], where g is the number of girls and b is the number of boys. Now let's look at what the question is asking.
"She wrote the ratio of boys to girls in 3 ways."
Note: boys to girls. Our original proportion is currently at girls to boys. Therefore these proportions are swapped. We can see that she messed this up.
Therefore, we need to swap the values.
So 13 to 15 becomes 15 to 13
13:15: becomes 15:13
[tex]\frac{13}{15}[/tex] becomes [tex]\frac{15}{13}[/tex].
Hope this helped!