What is a Bar Graph?

A bar graph is a chart or graphical representation of data. A bar chart, also known as a bar graph, is a graph or chart that displays categorical data using rectangular bars with heights or lengths equal to the values they represent. Typically, bar graphs show categorical and numerical variables grouped in class intervals. A bar graph is useful for comparing and analyzing a set of data.

Representation Using a Bar Graph

In mathematics, a bar graph is one method of data handling. Tables, bar graphs, pie charts, histograms, and frequency polygons can all be used to represent data. A bar graph is a graph that contains rectangular bars. Typically, the graph compares different categories.

Although bar graphs can be plotted vertically (bars standing up) or horizontally (bars lying flat from left to right), vertical bar graphs are the most common. This is because the length of the bars is proportional to the data measure. The horizontal (x) axis represents the categories, and the vertical (y) axis represents the values associated with those categories. The values in the graph below are percentages. For example, below bar graph below represents the birthday of students by month.

Characteristics of Bar Graph

• A bar graph has equal width bars or columns.
• The bases of all bars are the same.
• The height of the bar corresponds to the data value.
• Each bar is the same distance apart.

Uses of Bar Graph

The bar graph is a good way to compare items from different groups. The bar graph is a powerful visual to use in presentations and reports. They are popular because they enable the reader to identify patterns or trends much more easily than a table of numerical data.

Bar charts have a discrete domain of divisions and are typically scaled to fit all of the data on the graph. When the matching divisions do not have a regular order, the bars on the chart can be organized in any order. Pareto charts are bar charts that are organized from the highest to the lowest number.

How to Construct Bar Graph?

• Draw two perpendicular lines that intersect at a point O. The y-axis is represented by the vertical line, while the x-axis is represented by the horizontal line.
• To determine the height of each bar, select a suitable scale.
• Draw the bars at equal distances on the horizontal line.
• Raise the bars to the heights based on the data value on the vertical line.
• The distance between the bars should be the same.

Advantages of Bar Graph

• Displays a frequency distribution for each data category.
• Shows the relative numbers or proportions of various categories
• Visually summarizes a large data set.
• Clarifies trends better than tables do.
• At a glance estimates key values.
• Allows for a visual check of calculation accuracy and reasonableness.

Disadvantages of Bar Graph

• Requires further explanation.
• Can be easily manipulated to produce false impressions.
• Key assumptions, causes, effects, or patterns are not revealed.

What are the types of Bar Graphs?

The following are the various types of bar graphs:

Vertical Bar Graph

When displaying information in segments, bar graphs should be used. Vertical bar graphs are particularly useful for time series data, as you are aware. Vertical bar graphs are created when grouped data is represented vertically in a graph or chart with the help of bars, where the bars denote the measure of data. The data is represented on the graph's y-axis, and the values are represented by the height of the bars.

Horizontal Bar Graph

A horizontal bar graph shows data in a horizontal format. It is a graph with horizontally drawn bars. The vertical axis displays the data categories, while the horizontal axis displays the data values. Each bar's length is equal to the value corresponding to the data category, and all bars run across from left to right.

Grouped Bar Graph

Grouped bar charts are bar charts in which multiple sets of data items are compared, with a single colour used to denote a specific series across all sets. As with basic bar charts, both vertical and horizontal versions of grouped bar charts are available.

The grouped bar graph, also known as the clustered bar graph, represents the discrete value for multiple objects in the same category. Grouped bar charts necessitate three columns or rows of data from your data set: one for the series, one for the categories, and one for the values.

Stacked Bar Graph

A stacked bar graph (or stacked bar chart) is a chart that uses bars to compare data categories, but with the ability to break down and compare parts of a whole. Thus, each bar in the chart represents a whole, and each segment represents a different part or category of that whole.

The stacked bar graph is also known as the composite bar chart because it divides the aggregate into different parts. Each bar in a standard bar chart is divided into a number of sub-bars stacked end to end, each one corresponding to a level of the second categorical variable, and each part can be represented using different colors.

Double Bar Graph

A double bar graph is the same as a regular bar graph. The only difference is that it compares two data groups. A double bar graph, in other words, is a graphical representation of information that uses two bars next to each other at varying heights. The bars can be arranged in either a vertical or horizontal pattern. Thus, it is also known as a double bar chart.

Histogram

A histogram is a graphical representation of data that uses bars of varying heights. Each bar in a histogram categorizes numbers into ranges. Taller bars indicate that there is more data in that range. A histogram depicts the shape and distribution of continuous sample data. The most common graph for displaying frequency distributions is a histogram. It appears to be a bar chart, but there are significant differences between them.

Histograms are used to show distributions of variables, while bar charts are used to compare variables. Histograms plot quantitative data with ranges of the data grouped into bins or intervals, while bar charts plot categorical data.

Pie Chart

A pie chart (also known as a circle chart) is a circular statistical graphic divided into slices to show numerical proportion. The arc length of each slice in a pie chart (and thus its central angle and area) is proportional to the quantity it represents.

Common Mistakes

• The values of the axes give context to charts. When you mess with the axes, you get a visualization that paints a completely false picture.
• Unnecessary dimensions are used while decorating a bar chart.
• Mistakes with scales are among the most common graphical mistake.
• Not using annotations.

Context & Applications

• Bar graphs can be used to present information to customers, employees, and other businesses, such as sales figures.
• People can also use bar graphs for personal reasons, such as budgeting.
• This financial report includes a bar graph that depicts the company's monthly sales activity over the last year.
• A stock volume chart is a type of vertical bar graph that is commonly used.
• Bar graphs are used in some types of technical analysis.

Related Concepts

• Data visualization
• Data handling