Answer
By year 11 would expect the class to have 150 students
This is because it goes up by 9, 9, 9, 12, 4, 23, 14 etc.
Median is 9 students from the 7/8 changes so in 3 more years you would expect there to be 150 students. As the number of students seem to be greater.
The mean = 80 /7 = 11.4 student increase a year.
- but couldn't read question clearly as its not in full.
Explanation:
So we say add 10 each year = 10 x 3 = 30
30 +117 = 147 students this makes 3 years year 11
147+10 = 157 this makes 4 years time year 12.
I would go for the mean and say 3 years time.
As 11.4 x 3 = 34 students
117+34 = 151 students.