Two types of graphs that can be used to display qualitative data are the bar graph and the Cake chart. A bar chart is also known as a bar chart.

We are going to create a bar chart and pie chart using the frequency distribution and the relative frequency distribution of the smartphone type.

Relative frequency distribution

Use the frequency distribution to create a bar graph. Use relative frequency distribution to create a pie chart.

Display of qualitative data using a bar graph

How do I create a bar chart?

  • Put the smartphone type on the horizontal axis and the frequency on the vertical axis.
  • Draw a bar for each category. The bar is just a shape that looks like a rectangle.
  • The height the bar is the frequency the category.
Qualitative data bar graph

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

Display qualitative data using a pie chart

How to make a pie chart

A pie chart looks like a circle. A circle is 360 degrees.

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

The number of parts corresponds to the number of categories. Since we have 4 categories, the circle consists of four parts.

Each part has a square measure. Adding the angular dimensions of the 4 parts corresponds to 360 degrees.

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

For example, the Windows phone’s relative frequency is 0.2

0.2 × 360 degrees = 72 degrees

The window telephone is 72 degrees in a circle.

For Android 0.3 × 360 degrees = 108 degrees

For the 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

Qualitative data pie chart


0.3 = 30%

0.2 = 20%

0.375 = 37.5%

0.125 = 12.5%


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