Two different age groups were surveyed about the amount of time they spent on social media.
The results are shown on the two frequency
polygons below. The same time intervals were
used for both graphs.
a) How many 18-year old
students took part in
the survey?
12-year old students
18-year old students
80
80
70-
60
70-
Frequency
50
40
Frequency
30
20
60-
b) How many more 18-year
50
old students than 12-year
40
old students spent
30
between 25 and 35 mins
on social media?
10-
0
3more
0 10 20 30 40 50 60 70 80
Time (mins)
20-
10
0-4
0 10 20 30 40 50 60 70 80
Time (mins)