In order to find the relative frequency, we will use the frequency distribution table below and the following formula.

To find the **relative frequency** of a category, divide the frequency of that category by the sum of all frequencies.

We can express the relative frequency with a math formula.

Relative frequency of a category

Frequency of that category
Sum of all frequencies

The table below is a frequency table of type of smartphone. Let us find the relative frequency for the categories you see in the able above.

Relative frequency of Android phone

12
40

= 0.3
Relative frequency of Window phone

8
40

= 0.2
Relative frequency of Iphone

15
40

= 0.375
Relative frequency of Amazon's fire phone

5
40

= 0.125
A relative frequency distribution is a table that shows the relative frequency for **all** categories as shown below.

Notice that the sum of the relative frequencies is always equal to 1.

The percentage of a category is found by multiplying the relative frequency of that category by 100.

Percentage of Android phone = 0.3 × 100 = 30%

Relative frequency of Window phone = 0.2 × = 20%

Relative frequency of Iphone = 0.375 × 100 = 37.5%

Relative frequency of Iphone = 0.125 × 100 = 12.5%

Since, the relative frequency of Window phone is 20%, we can conclude 20% of the people in the sample said that they own a Window phone.