13 The headteacher of a school wishes to collect the opinions of the students on a new timetable structure.
To do this, a random sample of size 50 , stratified by year group, will be selected.
The school has a total of 720 students.
The number of students in each of the year groups at this school is shown below.
| Year group | 10 | 11 | 12 | 13 |
| Number of students | 200 | 240 | 150 | 130 |
13
- Find the number of students from each year group that should be selected in the stratified random sample.
13 - State one advantage of using a stratified random sample.