Calculate median from the following data :

Explanation

Since , we are given cumulative frequencies , firstly we find simple frequencies.

M= Size of `((N)/(2))` th item
= Size of `((125)/(2))` th item = Size of 62.5 th item
Hence , median in the class 30-40.
` M= l_(1)+(N/(2)-c.f.)/(f)xxi`
`=30+(125/(2)-40)/(36)xx10=30+(62.5-40)/(36)xx10`
`=30+(22.5)/(36)xx10=30+6.25=36.25`
Median = 36.25 marks.