Question

Must the class intervals be continuous for mean,median,mode?

Answer 1

no need for example take this data

class-interval or marks	mid point of the interval x	no of students (f)	fx
0-10	5	4	20
20-30	25	6	150
40-50	45	8	360
60-70	65	6	390
80-90	85	3	255

here for this data the class interval is not continuous, but still we can find the mean median and mode for this data here total sum of frequencies N =27 mean will be = (sum of all fx)/N = (20+150+360+390+255)/27 = 1175/27 mean= 43.511 same goes for median and mode therefore it need not be continuous infact every dicrete data is a continuous data i.e, f will be 0 for that discrete interval, so we dont consider much