Question

Convert the following data into grouped frequency distribution:
$3,4,5,6,6,5,4,3,2,2,2,1,7,7,8,2$

Answer 1

First arrange the data in ascending order
$1,2,2,2,2,3,3,4,4,5,5,6,6,7,7,8$
The largest number $=8$
The smallest number $=1$
Range $=$ largest number $-$ smallest number $=8-1=7$
We shall calculate an approximate group size, by dividing the range by the number of groups we want.
If we want $3$ groups, then Divide range with number of groups $=\frac{7}{3}=2.333$
The class width will be $2$, Starting from $1$.

Class interval	Frequency
$1-3$	$7$
$4-6$	$6$
$7-9$	$3$