American Institute of Certified Planners (AICP) Practice Exam

A 'Sample' in statistics is defined as what?

1. The entire population

2. A subset of the population

3. A large sample size

4. The mean of the population

The correct answer is: A subset of the population

A 'Sample' in statistics is defined as a subset of the population, which aligns perfectly with the correct answer. This means that when researchers want to draw conclusions or make inferences about a larger group (the population), they will often select a smaller group (the sample) to study. By analyzing the sample, statisticians can apply their findings to the wider population, assuming that the sample is representative. The focus on having a subset enables two important aspects: it allows for manageable data collection and analysis, and it facilitates statistical testing where estimates can be made about the population based on sample data. Statistical methods are designed with the understanding that samples are used to infer about populations, rather than examining the entire population, which may be impractical or costly. The concept of a large sample size relates to the idea of increased reliability and validity in statistical analyses, but it doesn’t define what a sample is. Similarly, the mean of a population is a summary statistic derived from data which may come from a sample, yet it does not define what a sample is. Lastly, the entire population represents the total group being studied and not a subset. Thus, defining a sample accurately as a subset is crucial for effective statistical practice.