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? Mode = 61 + 10
7

4

10 61

4 3

4

u  u



= 61 + 61 57 667
7

40

 ˜ ˜

Therefore, the required mode is 66˜ 714
Example 14. Find the mode from the frequency distribution table below :
Solution : Here, maximum numbers Class Frequency
of frequency are 25 which lie in the 41  50 25
class (41–50). So it is evident that 51  60 20
mode is in this class. We know that 61  70 15

Mode = h

f f

f

L u





1 2

1

71  80 8

Here, L 41 [If the frequency is maximum in the first class, the frequency of
previous class is zero]
f 1 25  0
f 2 25  20 5

? Mode = 41 + 10
25 5

25

u



= 41 + 10 51 833
30

25

u  ˜

= 49 ˜ 33
Therefore, required mode is 49˜ 33
In classified data, if the first class is mode class the frequency of previous class is
considered to be zero.
Example 15. Determine the mode of the following frequency distribution table :

Solution : The maximum numbers of Class Frequency

frequency are 25 which lie in the class 10  20 4

(41 – 50). So it is obvious that this class is the 21  30 16

class of mode. We know that, 31  40 20

Mode = h

f f

f

L u





1 2

1 41 ^50 25

Here, L 41
f 1 25  20 5