[填空题]
The following cumulative frequency diagram shows the 9wy,u hhh5af15:jm9(ofhs( 9vgqbq 2v fapg5distance stu5 dp(u;vvfx3 idents need to travel to get to s puxv3(iv;5f dchool.
1. Find the median distance a student travels to school.
2. Find the number of students that travel between 2 $\mathrm{~km}$ and 4 $\mathrm{~km}$ to get to school.
3. Find the percentage of students that travel more than 4.5 $\mathrm{~km}$ to get to school. %