問題文
A city asks 900 of its 240,000 residents how long they commute. The analyst computes the average commuting time of the 900 people who answered and wants to state precisely what that group and that figure are. Which statement is accurate?
選択肢
- The 900 residents who answered form a universe, and the average computed from them is a parameter fixed for that population.
- The 900 residents who answered form a universe, and the average computed from them is a statistic calculated for that sample.
- The 900 residents who answered form a sample, and the average computed from them is a parameter fixed for that population.
- The 900 residents who answered form a sample, and the average computed from them is a statistic calculated for that sample.