What term describes a quantitative measure used to describe a sample?

The question asks for the term that describes a quantitative measure used to describe a sample.

• A parameter is a quantitative measure that describes a population.
• A statistic is a quantitative measure that describes a sample.
• Statistics (plural) refers to the field of study or a collection of statistics.
• Data refers to the raw facts or figures collected, not a descriptive measure of the sample itself.

Therefore, the correct term is "Statistic".

The final answer is $\text{b. Statistic}$.