Question

how to make a discrete class to a continuous class for e.g.--- 0-17 67-85

Answer 1

Solution:-

Please consider the following distribution.

      x                                                         f
  10-14                                                     8 
  15-19                                                    10
  20-24                                                    25
  25-29                                                    12
  30-34                                                     7

The given frequency distribution is not continuous.
The difference between the lower limit of a class and the upper limit of the preceding class is 1 i.e. h = 1 
To convert the given frequency distribution into a continuous frequency distribution, we will subtract
= h/2
= 1/2
= 0.5
from each lower limit and add 0.5 to each upper limit.
The continuous frequency distribution obtained will be as follows.
    
        x                                                   f
   9.5-14.5                                            8
 14.5-19.5                                           10
 19.5-24.5                                           25
 24.5-29.5                                           12
 29.5-34.5                                            7

This way you can convert a discrete class into a continuous class.