Question: How to make Quantitative Frequency Distributions and Histograms in pandas?
Relative Statistics topic: https://www2.southeastern.edu/Academics/Faculty/dgurney/Math241/StatTopics/HistGen.htm

```python
pd.DataFrame({'amount': ['12', '15', '20', '22', '14', '14', '15', '27', '21', '18', '19', '18', '22', '33', '16', '18', '17', '23', '28', '13']})
```