NCERT Class 10 Mathematics

278 MATHEMATICS

Here n = 100, which is even. The median will be the average of the

2

nth and the

1

2

n ✁

✄ ✂ ☎

✆ ✝

th observations, i.e., the 50th and 51st observations. To find these

observations, we proceed as follows:

Table 14.10

Marks obtained Number of students

20 6

upto 25 6 + 20 = 26

upto 28 26 + 24 = 50

upto 29 50 + 28 = 78

upto 33 78 + 15 = 93

upto 38 93 + 4 = 97

upto 42 97 + 2 = 99

upto 43 99 + 1 = 100

Now we add another column depicting this information to the frequency table
above and name it as cumulative frequency column.

Table 14.11

Marks obtained Number of students Cumulative frequency

20 6 6

25 20 26

28 24 50

29 28 78

33 15 93

38 4 97

42 2 99

43 1 100