True.

If a data point is at the 81st percentile, it indeed means that 81% of the population (or data set) is at or below that data value. In percentile terms, the 81st percentile marks the point below which 81% of the observed values fall.

Would you like more details or have any questions on percentiles or similar concepts?

Here are five related questions to explore further:

1. What is the difference between percentiles and quartiles in data analysis?
2. How do you calculate the percentile rank of a given data point in a sample?
3. What is the significance of the 50th percentile in statistics?
4. Can percentiles be used in normal distribution, and if so, how?
5. How do percentiles help in understanding the spread of data in a population?

Tip: Percentiles are helpful for understanding the relative position of a data point within a data set, especially when comparing individual scores to a group.