ECO 391 Exam 1 questions & answers
2025/2026
Random Sampling - correct answer ✔✔probability of being in the sample is the same as the
probability that one occurs in the population
Selection Bias - correct answer ✔✔Systematic exclusion of groups in your sample
Z-Score of 95% CI - correct answer ✔✔1.96
Stratified Random Sampling - correct answer ✔✔Divide population into mutually exclusive ad
collectively exhaustive groups, called strata
Clustered Sampling - correct answer ✔✔Divide population into separate groups, called clusters.
Then, a simple random sample of clusters is selected from the population.
What does it mean for an estimator to be consistent? - correct answer ✔✔the sample size
increases, the sampling distribution of the estimator becomes increasingly concentrated at the
true parameter value
What does it mean for an estimator to be unbiased? - correct answer ✔✔accurate statistic
that's used to approximate a population parameter
What does it mean for an estimator to be efficient? - correct answer ✔✔test needs fewer
observations
2025/2026
Random Sampling - correct answer ✔✔probability of being in the sample is the same as the
probability that one occurs in the population
Selection Bias - correct answer ✔✔Systematic exclusion of groups in your sample
Z-Score of 95% CI - correct answer ✔✔1.96
Stratified Random Sampling - correct answer ✔✔Divide population into mutually exclusive ad
collectively exhaustive groups, called strata
Clustered Sampling - correct answer ✔✔Divide population into separate groups, called clusters.
Then, a simple random sample of clusters is selected from the population.
What does it mean for an estimator to be consistent? - correct answer ✔✔the sample size
increases, the sampling distribution of the estimator becomes increasingly concentrated at the
true parameter value
What does it mean for an estimator to be unbiased? - correct answer ✔✔accurate statistic
that's used to approximate a population parameter
What does it mean for an estimator to be efficient? - correct answer ✔✔test needs fewer
observations
