Which of the following is true about research based on a sample?

• A. Research based on a sample does not require any assumptions about the $\mathrm{population}$.
• B. The results from a $\mathrm{sample}$ are used to estimate characteristics of the entire $\mathrm{population}$.
• C. Sampling eliminates all uncertainty in statistical inference.
• D. A $\mathrm{sample}$ always provides the exact values of the $\mathrm{population}$ parameters.

Answer: (B)

Verified step by step guidance

1. Understand that research based on a sample involves collecting data from a subset of the population to make inferences about the entire population.
2. Recognize that the goal of sampling is to estimate population parameters (such as mean, proportion, variance) using sample statistics.
3. Recall that sampling does not eliminate uncertainty; instead, it introduces sampling error, which is the difference between the sample estimate and the true population parameter.
4. Know that assumptions about the population (such as randomness, independence, and distribution) are often necessary to justify the use of certain statistical methods and to make valid inferences.
5. Conclude that the correct statement is: 'The results from a sample are used to estimate characteristics of the entire population,' because samples provide estimates, not exact values, and sampling involves uncertainty.