Which of the following is a good point estimator for the population mean?

• A. The sample median
• B. The sample mode
• C. The sample variance
• D. The sample mean $\overline{x}$

Answer: (D)

Verified step by step guidance

1. Understand that a point estimator is a statistic used to estimate a population parameter based on sample data.
2. Recall that the population mean is the average value of a population, and we want an estimator that is unbiased and efficient for this parameter.
3. Consider the sample mean, denoted as \(\overline{x}\), which is calculated by summing all sample observations and dividing by the sample size: \(\overline{x} = \frac{1}{n} \sum_{i=1}^n x_i\).
4. Recognize that the sample mean is an unbiased estimator of the population mean, meaning its expected value equals the population mean.
5. Note that other options like the sample median, sample mode, and sample variance estimate different aspects of the data and are not the best point estimators for the population mean.