The following table gives the marks obtained by the students of a class in an exam out of 50.
MarksNo. of StudentsBelow 105Below 2010Below 3023Below 4031Below 5040
(i) Convert the cumulative frequency distribution into a regular frequency distribution.
(ii) Find the mean.
27.75
MarksNo. of Students0−10510−20520−301330−40840−509
Class Intervalxififixi0−10552510−201557520−30251332530−4035828040−50459405
∑fi=40 & ∑fixi=1110
Mean
=111040
=27.75