[填空题]
The following cumulative frequency diagram s1vbry -y 1-ww:m radl)hows tqo5)+yoeha1ja8 yq u-he distance students need to travel to get to 5-ah 8jeqo1oy+qu ya)school.
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. %