Persentili

Persentili is a statistical term referring to a value below which a certain percentage of observations in a group of observations fall. For example, the 20th persentili is the value below which 20% of the data falls. Persentili are often used to understand the distribution of data and to compare values within a dataset.

There are several ways to calculate persentili, with slight variations in methodology. The most common approach involves ordering the data from smallest to largest. Then, the position of the persentili is determined by multiplying the desired percentage by the total number of observations. If this product is not a whole number, it is typically rounded up to the nearest whole number to find the rank of the persentili. If the product is a whole number, the persentili can be the average of the value at that rank and the value at the next rank.

Persentili are widely used in various fields. In education, they are used to report standardized test scores, indicating how a student's performance compares to others. In healthcare, persentili are used to track growth patterns in children, such as height and weight charts. In finance, they can be used to analyze the distribution of income or asset values. Understanding persentili helps in interpreting relative positions within a dataset.