Question

Why does the mean obtained from ungrouped data differ from grouped data? ( lesson- statistics: NCERT- grade 10)​

Answer 1

Answer:

Mean for grouped data :

In these distribution, it is assumed that frequency of each class interval is centered around its mid-point i.e class marks

whereas mean for ungrouped data :

example of ungroup Frequency table

marks obtained no of students

25 4

35 10

45 23

65 34

and the formula to find it is given in picture.

Hope it will help you