Area Chart

An area chart is a type of chart used to represent data points over a continuous scale, usually time. It is similar to a line chart, but the area between the line and the horizontal axis is filled with color. This makes it useful for showing both trends and the magnitude of values.

Example 1: Monthly Sales

The monthly sales of a company are given below:

Solution:

To represent this data using an area chart:

1. Take months on the X-axis.
2. Take sales (in units) on the Y-axis.
3. Plot the points: (January,20), (February,30), (March,25), (April,40), (May,50), (June,45)
4. Join the points with a line.
5. Shade the area between the line and the X-axis.

Example 2: Temperature Over a Week

The temperatures recorded over seven days are:

Solution:

The days are placed on the X-axis and temperature on the Y-axis. After plotting and joining the points, the region below the line is shaded.

Interpretation: The temperature reaches its highest value on Saturday and then decreases on Sunday.

Types

1. Simple Area Chart

A simple area chart contains one data series. It is useful for observing the change in one quantity over time.

Example: Monthly revenue of a company.

2. Stacked Area Chart

A stacked area chart contains multiple data series stacked on top of one another. It can be used to show how different components contribute to a total and how those contributions change over time.

Example: A company may track revenue from:

• Product A
• Product B
• Product C

The stacked areas show both the individual contributions and the overall total.

3. 100% Stacked Area Chart

A 100% stacked area chart represents each time period as 100%. It focuses on the proportion or percentage contribution of each category rather than the absolute values.

Example: It can show the percentage share of different products in total sales over time.

Applications

Area charts are commonly used in:

• Business: Revenue and sales trends
• Finance: Changes in financial quantities over time
• Economics: Economic indicators
• Web analytics: Website traffic and users
• Technology: System usage and resource consumption
• Education: Student performance trends
• Science: Changes in measured quantities over time
• Marketing: Campaign performance over time

Practice Questions

Q1. A company's monthly revenue is given below:

Q2. The following table shows the number of visitors to a website:

Q3. The production of a manufacturing company is:

Q4. The population of a city over eight years is given below: