Consider the data


The difference of the upper limit of the median class and the lower limit of the modal class is



Here, N/2 = 67/2 = 33.5 which lies in the interval 125 – 145.


Hence, upper limit of median class is 145.


Here, we see that the highest frequency is 20 which lies in 125 - 145. Hence, the lower limit of modal class is 125.


Required difference = Upper limit of median class – Lower limit of modal class = 145 – 125 = 20

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