the marks obtained by 120 students in an english test are given below
marks:0-10,10-20,20-30,30-40,40-50,50-60,60-70,70-80,80-90,90-100
no.of students:5,9,16,22,26,18,11,6,4,3
draw the ogive in a graph paper and hence,estimate:
(a)the median marks
(b)the no .of students who did not pass the test if the pass percentage was 40
(c)the upper quartile marks
Answers
Answer:
ANSWER
Marks No. of students(f) 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
On the graph paper, we plot the following points:
(10,5),(20,14),(30,30),(40,52),(50,78),(60,96),(70,107),(80,113),(90,117),(100,120).
(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
=10.
(iii) The number of students who did not pass the test if the minimum pass marks 40 is 52.
Answer:
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
Step-by-step explanation:
Median =120 +1/2
=60.5th term