What are quantiles used for in data analysis?

Quantiles are statistical tools that divide a dataset into equal subgroups, which allows for a clearer analysis of the distribution of the data. By using quantiles, such as quartiles, quintiles, or deciles, one can determine specific cut-off points in the data that segment it into intervals containing an equal number of observations. This division is particularly useful for understanding how data is spread and can reveal insights into variability and potential outliers within the dataset.

For example, if you have a dataset that is broken into quartiles, each quartile represents 25% of the data points, which encourages a more granular analysis than simply looking at measures like the average. This characteristic makes quantiles invaluable in assessing skewness, identifying the spread of data, and making informed decisions based on data distribution.

Other options, such as determining averages, identifying trends, or measuring total population, do not capture the specific function of quantiles in dividing data into equal parts, which makes them less suitable in this context.