���
=
42
n=42.
Square root of 
42
42 is approximately 
6.48
6.48.
Rounded to the nearest integer, we get 
6
6.
The range of the data is 
73.5
−
45.1
=
28.4
73.5−45.1=28.4.
Class width 
≈
28.4
6
≈
4.73
≈ 
6
28.4
​
 ≈4.73.