Question

2) Following are the marks obtained by 120 students in ICSE Mathematics Paper

Marks 10 - 20 20 - 30 30 - 40 40 - 50 50 - 60 60 – 70 70 – 80

f 1 3 11 21 43 32 9

Represent the above data by means of an ogive and use it to find

(i)Median (ii)Upper Quartile (iii)Lower Quartile (iv) Inter- quartile range (v)% of students who are

getting more than 65 marks.​

Answer 1

Answer:

Answer

Marks No. of students(f) Cumulative Frequency

0−10 5 5

10−20 9 14

20−30 16 30

30−40 22 52

40−50 26 78

50−60 18 96

60−70 11 107

70−80 6 113

80−90 4 117

90−100 3 120

n=120

=10.

(i) Median =(

2

n

)

th

term [∵n=120, even]

=

2

120

=60

th

term

From the graph 60

th

term =42

(ii) The number of students who obtained more than 75% marks in test

=120−110