4/84 as a percentage is 4.76%. This small number shows how little of a whole 4 parts represent when the whole has 84 parts.
The fraction 4/84 can be reduced to 1/21, which is still a tiny slice of the total. Thinking of it as a percent makes it easier to compare with other values you might see on a chart or a bill.
In everyday situations, 4.76% might represent a small discount, a minor tax rate, or a tiny portion of a budget. Knowing the percentage helps you quickly see how the fraction fits into larger numbers.