Define percentile and interpret the 75th percentile.

• A. A percentile is a value above which a given percentage of observations fall; the 75th percentile means 75% are above.
• B. A percentile is a value below which a given percentage of observations fall; the 75th percentile means 75% are above.
• C. A percentile is a value below which a given percentage of observations fall; the 75th percentile means 75% are below.
• D. It is the same as the mean

Answer: (C)

Percentiles describe where a value sits relative to the entire data set by marking a cutoff so that a specified portion lies at or below that point. The 75th percentile is the cutoff where 75% of observations are at or below it, and the remaining 25% are above it. That framing—below or equal to the cutoff accounts for most practical interpretations—makes this the correct way to interpret the 75th percentile. It’s not about how many are above; it’s about how many are below. And a percentile is different from the mean, which is just the average of all values.