To understand a histogram better, it helps to know what it shows and how to read it.

What is a Histogram Made Of?

1. Bars: Each bar shows a range of values (called bins). The height of the bar tells you how many data points are in that range.

2. X-Axis (Horizontal): This is the bottom part of the histogram that shows the different ranges of data. For example, if we're looking at the ages of students, the ranges might be 10-12 years, 13-15 years, and so on.

3. Y-Axis (Vertical): This side shows how often something happens. If a bar is 5 tall, it means 5 students fall within that age range.

How to Read a Histogram?

• Look at the Shape: Check if the histogram is symmetrical (balanced), skewed (one side is longer), or has two peaks (bimodal). This shows how the data is spread out.

• Check the Frequencies: See how tall the bars are. Taller bars mean that more data points fall into that range. For example, if the tallest bar is 10, that means 10 data points are in that bin.

• Find Averages: You can get an average (mean) using the middle points of each bin and how many points are in them. You can estimate the mean using this formula:

$$\mu \approx \frac{\sum (x_i \cdot f_i)}{N}$$

Here, $x_i$ is the middle point of each bin, $f_i$ is how many data points are in each bin, and $N$ is the total number of data points.

By following these simple steps, you can understand what a histogram is telling you about the data.