# Lesson 2: Visualizing Data

```
Something | Frequency
India | 10
China | 14
England | 100
```

- Relative frequency == proportion
- Defined as: frequency / total
- India = 10 / 124 == 0.08
- Always >= 0 and <= 1

- Percent = proportion * 100
- Histogram
- Interval/bin/bucket
- Grouping things like ages: 0 - 19, 20 - 39, 40 - 59

- Frequency is always y-axis
- Variable is on x-axis

- Bar graph
- Different from histogram, each variable is a distinct value
- x-axis is sometimes categorical rather than numerical/quantitative

- Normal distributions
- Skewed distributions
- Peaks toward left or right