What role do quartiles play in a box plot?

Quartiles are essential components of a box plot because they help to summarize and represent the distribution of a dataset. Specifically, the box plot visually displays the median, which is the second quartile, along with the first and third quartiles that indicate the spread of the middle 50% of the data. By illustrating the quartiles, the box plot provides insights into the central tendency of the data (where most values fall) and the variability (how spread out the data is).

The first quartile (Q1) marks the 25th percentile, while the third quartile (Q3) marks the 75th percentile, allowing for an easy assessment of where the lower and upper quarters of the data lie. Additionally, this representation highlights any potential outliers and the overall shape of the distribution, making it a valuable tool for statistical analysis. Overall, the use of quartiles in a box plot effectively conveys information about both the distribution and central tendency of the dataset, aiding in understanding its characteristics.