Two different age groups were surveyed about the amount of time they spent on social media.
The results are shown in the two frequency
polygons below. The same time intervals were
used for both graphs.
80+
50
Frequency
11-year old students
15-year old students
801
70-
70
60
60
50
640
L 30
30
20
10
10
04
0+
0 10 20 30 40 50 60 70 80 • 10 20 30 40 50 60 70 80
Time (mins)
Time (mins)
Frequency
a) How many 15-year old
students took part in
the survey?
(1)
b) How many more 15-year
old students than 11-year
old students spent
between 35 and 45 mins
on social media?
20
(1)
Total marks: 2
SES
No

1.4

2.3

step-by-step explanation:

the formula for the constant of variation is

y= kx

divide each side by x

y/x =kx/x

y/x =k

we know a and y

1.   y/x = k

4/1 =4

check the other values to make sure they are the same

8/2 = 4   12/3 =4   and 16/4 =4  

the constant of variation is 4

2.   y/x = k

3/1 =3

check the other values to make sure they are the same

6/2 = 3   9/3 =3   and 12/4 =3  

the constant of variation is 3

is there a question here?

step-by-step explanation:

( - 4 , -7 )

all the lines must parallel  

step-by-step explanation:

coordinates of c = ( - 1 , 2 )

3 units left = ( -4 , 2 )

9 units down = ( - 4 , 11 )