The lengths of 40 leaves of a plant are measured correct to the nearest millimetre, and the data obtained is represented in the following table :

Find the median length of the leaves.(Hint: The data needs to be converted to continuous classes for finding the median, since the formula assumes continuous classes. The classes then change to 117.5- 126.5,126.5 - 135.5,..171.5 -180.5.)

Explanation

The data needs to be converted to continuous classes for finding the median since the formula assumes continuous classes. The classes then change to `(117.5−126.5,126.5−135.5,...,171.5−180.5)`


Converting the given table into exclusive form and preparing the cumulative frequency table, we get


We have, `n=40`


`=>n/2=20`


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