Compute the mode from the following series:


Size



45 - 55



55 - 65



65 - 75



75 - 85



85 - 95



95 - 105



105 - 115



Frequency



7



12



17



30



32



6



10


Here, the maximum class frequency is 32.

The class corresponding to this frequency is the modal class. ⇒ modal class = 85 - 95


∴ lower limit of the modal class (l) = 85


Modal class size (h) = 10


Frequency of the modal class (f1) = 32


Frequency of class preceding the modal class (f0) = 30


Frequency of class succeeding the modal (f2) = 6


Mode is given by,



⇒


⇒


⇒ Mode = 85 + 0.71 = 85.71


Hence, the mode is 85.71.


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