Question

n = 455, then the recommended number of classes is

Answer 1

One rule to help decide on the number of classes is Sturge’s formula:

$$с=1+\lfloor\log_2 n\rfloor=1+\lfloor3.322\log n\rfloor$$

where $c$ is the number of classes and $n$ is the number of observations in the data set.

$$с=1+\lfloor\log_2 455\rfloor=9$$

9 classes.