Proportions

The proportions of values in the categories (also called the relative frequencies of the categories) are the frequencies divided by the total number of values.

Percentages

The proportions are often expressed as percentages — simply the proportions multiplied by 100. For example, a proportion of 0.034 is more concisely expressed as 3.4% but contains identical information. It is usually easier to quickly compare a column of percentages than the corresponding column of proportions.

Percentages are usually easier to interpret than the raw frequencies, so frequency tables are often augmented with an extra column of percentages.

Tanzania drinking water

The frequency table below shows the main source of drinking water for all rural households in Tanzania in the dry season of 2002/3.

Choose the option Count & proportion under the frequency table to see the proportion of the households using water from each source.

Finally, choose the option Count & percentage to express the proportions as percentages. Although the percentages are simply 100 times the corresponding proportions, the information in the data stands out better when percentages are used.