The graph above shows the cumulative frequency curve of the distribution of marks in a class test. What percentage of the students scored more than 20 marks?
Attached Figure / Diagram
A
68%
B
40%
C
17%
D
8%
Verified Correct Answer: B.
Step-by-Step Mathematical Solution
class mark x
Cumulative. frequency
frequency
9
1
1
14
6
5
19
15
9
24
17
2 ↓
29
24
7 ↓
34
25
1 ↓
Total frequency = 25.
% students scoring over 20 marks = \(\frac{10}{25}\) x 100% = 40%
y-axis (Scale of the graph: 1cm to 0.5 units)
NOTE: (frequency of scores greater than 20 starts from 2 and ends at 1)
(To get frequency, subtract the cumulative frequency from down to upward)
Source: Myschool Past Questions Archive (Record #33117)