What is a percentile?

• A. A point that splits the data into 100 equal parts.
• B. The mean of the data set.
• C. A value that splits data into two parts.
• D. A value that describes the spread.

Answer: (A)

A percentile is a value that divides the data so that a specified proportion of observations fall at or below it, effectively cutting the dataset into 100 equal parts. For example, the 25th percentile is the value below which 25% of observations fall, the 50th percentile is the median (the point that splits the data into two halves), and the 90th percentile is the value below which 90% fall. This concept is about position in the distribution, not about the data’s center or its spread. The mean is a measure of center, not a percentile. A value that splits data into two parts specifically describes the median, not percentiles in general. A value describing the spread refers to variability measures like range or standard deviation, not percentile cutoffs.