Definition
Relative frequency
Relative frequency tells what fraction of all trials or observations had a chosen result.
What it means
Count the result you care about, then compare that count with everything you counted. This changes a raw count into a fair-share number, so groups with different totals can be compared. The whole in the denominator must be the correct total for that result.
Remember it
Part count ÷ whole count: how much of the total had this result?
Example
A spinner is used 25 times and lands on blue 9 times. The relative frequency of blue is 9 ÷ 25 = 9/25 = 0.36, or 36%.
Watch for
Using 9 ÷ 30 would be wrong if only 25 spins were recorded; the denominator must match the relevant total.
Common mix-up
Frequency is the count, 9. Relative frequency is the share of the total, 9/25.
Exact meaning
Relative frequency is the number of times a specified outcome or category occurs divided by the relevant total number of trials or observations. It can be written as a fraction, decimal, or percentage and is between 0 and 1 inclusive.