Sat, 09 May 2026 12:45:26 +0000

#### 18000A statistician is developing a new method to estimate population variance. She samples 10 values from a normally distributed population: 12, 15, 18, 21, 24, 27, 30, 33, 36, 39. What is the sample variance using the Bessel-corrected formula?
In an era of data-driven decision-making, emerging statistical approaches aim to refine how we understand variability in populations—critical for research, finance, healthcare, and beyond. This method, recently adapted by a statistician engaged in methodological innovation, reflects growing interest in precise estimation techniques, especially when dealing with smaller samples. Given a carefully selected dataset reflecting expected normality, understanding the correct calculation of sample variance ensures reliable inference. The values tested form a clear arithmetic sequence upward from 12 to 39—ideal for demonstrating statistical concepts in real-world patterns. This approach helps illuminate how modern statisticians adjust classical formulas for better accuracy, even with limited data. Understanding the significance of Bessel’s correction
The distinction between population and sample variance hinges on a key statistical adjustment: Bessel’s correction. When estimating the population variance from a sample, the divisor uses \(n - 1\) rather than \(n\) to account for the loss of one degree of freedom. This adjustment produces a less biased estimate, especially valuable in small samples where \(n\) is close to the true population size. In practical terms, this correction acknowledges that sample data likelihood underestimates true variability if treated as complete population data. The statistician’s work emphasizes refining this correction in estimation workflows, improving robustness in applications where data is scarce but insights are critical. The step-by-step calculation of sample variance
To compute sample variance, begin with the labeled dataset:
12, 15, 18, 21, 24, 27, 30, 33, 36, 39. First, determine the sample mean, which serves as