# Display of qualitative data

Two types of graphs that can be used to display qualitative data are the **bar graph** and the **pie chart**. A bar graph is also called a bar chart.

We will make a bar graph and a pie chart using the frequency distribution and the relative frequency distribution of type of smartphone.

To make a bar graph, use the frequency distribution.

To make a pie graph, use the relative frequency distribution.

**How to make bar graph.**

Use a coordinate system.

Put the type of smartphone on the horizontal axis and the frequency on the vertical axis.

Draw one bar for each category. The bar is just a shape looking like a rectangle.

The **height** of the bar is the **frequency** of the category.

Notice that the distance between the bars is the same. Furthermore, the width of the bars is the same.

**How to make a pie graph**

A pie graph looks like a circle. A circle has 360 degrees.

The entire pie represents either the entire sample or the population.

The number of parts is the same as the number of categories. Since we have 4 categories, the circle will have four parts.

Each part will have an angle measure. Adding the angle measures of the 4 parts will equal to 360 degrees.

To find out how big a part will be, just multiply the relative frequency of a category by 360 degrees.

For example, the relative frequency of Window phone is 0.2

0.2 × 360 degrees = 72 degrees

Window phone will occupy 72 degrees in the circle.

For Android, 0.3 × 360 degrees = 108 degrees

For Iphone, 0.375 × 360 degrees = 135 degrees.

For Amazon’s fire phone, 0.125 × 360 degrees = 45 degrees

Notice that 72 + 108 + 135 + 45 = 360

**Percentage**

0.3 = 30%

0.2 = 20%

0.375 = 37.5%

0.125 = 12.5%

Frequency distribution of quantitative data

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