Definition: Relative frequency is the fraction or percent of the total that falls in a category, found by dividing its count by the total count.
What is relative frequency?
It turns a raw count into a share. Frequency says how many, and relative frequency says what portion.
How do you compute it?
Divide the count by the total. In a class of 25 students, 9 walk to school. The relative frequency is 9 / 25 = 0.36, or 36 percent.
Why use it?
It lets you compare groups of different sizes. Class A has 9 walkers out of 25, and class B has 12 out of 40. Class A’s share is 36 percent and class B’s is 30 percent, so class A has the higher share even though class B has more walkers.
How does it appear in a two-way table?
Compute relative frequencies by row, column, or overall. Each set of shares adds to 100 percent.
How does it link to probability?
For a random student in class A, the chance of choosing a walker is 0.36, matching the relative frequency.
What is a common mistake?
Dividing by the wrong total, or comparing counts when the group sizes differ. Always check the denominator.