To find the relative frequency, we use the following frequency distribution table and formula. To find that relative frequency Divide the frequency of this category by the sum of all frequencies. We can express the relative frequency using a mathematical formula.

Relative frequency of a category

Frequency of this category
/.
Sum of all frequencies The above table is a frequency table of the smartphone type. Let’s find the relative frequency for the categories you can see above.

Relative frequency of the Android phone

12th
/.
40

= 0.3

Window phone relative frequency

8th
/.
40

= 0.2

Relative frequency of the Iphone

fifteen
/.
40

= 0.375

Relative frequency of the Amazon fire phone

5
/.
40

= 0.125

A relative frequency distribution is a table that shows the relative frequency for all Categories as shown below. Note 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.

Android phone percentage = 0.3 × 100 = 30%

Relative frequency of the window phone = 0.2 × = 20%

Relative frequency of Iphone = 0.375 × 100 = 37.5%

Iphone relative frequency = 0.125 × 100 = 12.5%

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