Understand the use of percentiles.

Percentiles are statistical measures that indicate the relative standing of a value within a dataset. For example, the 50th percentile, or median, divides the data into two equal halves, while the 25th and 75th percentiles represent the lower and upper quartiles, respectively. Understanding percentiles helps geographers analyze data distributions, identify trends, and make comparisons across different datasets. By using percentiles, one can better understand how individual data points relate to the overall dataset, which is crucial for effective data interpretation and decision-making in geographical studies.