What are frequency and cumulative distributions?

Frequency distribution is also known as interval distribution or differential distribution. It describes the percentage of particles in a particle size band, e.g., between 1 and 2μm. Cumulative distribution is also known as integral distribution. It describes the percentage of particles that are larger or smaller than a certain particle size value, which can be calculated through the cumulative addition of interval distributions.

The red curve below represents the cumulative distribution curve corresponding to the left ordinate. The particles included in the red area are equivalent to those in the green and blue areas under the frequency distribution curve.

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