Estimating Population Mean with Sample Average
Suppose we want to learn about the average height in the population, which unbeknownst to us is 66 inches. If we take a sample of a few people and use their average height to estimate , on average, will be equal to 66.
In this problem, we are exploring the concept of point estimation, which is a fundamental idea in inferential statistics. The problem highlights a key attribute of sample means: the unbiasedness when estimating a population mean. The average height of a sample, in this case, provides an unbiased estimator for the actual average height of the entire population. Understanding this concept is crucial because it shows that the expected value of the sample mean equals the population mean, implying that, on average, the estimates are correct even if sample estimates may vary due to sampling variability.
This problem also touches on the Law of Large Numbers, stating that as the size of the sample increases, the sample mean will get closer to the population mean. Although this problem does not require calculating or working directly with sample data, it introduces why sampling is an effective approach in statistics to estimate population parameters when it's impractical to measure the entire population. Therefore, point estimation becomes a useful tool in various fields to infer characteristics about populations based on sample data.
Additionally, in real-world applications of this concept, statisticians often ensure that samples are randomly selected to maximize the reliability and validity of their estimates. The simplicity of this problem should not detract from its demonstration of how sampling techniques form a backbone of statistical inference, ultimately allowing for effective decision-making based on data.
Related Problems
Independent identically distributed normal variables problem: Given independent identically distributed normal random variables with unknown mean mu and variance , estimate mu and from these observations using maximum likelihood estimation.
Using Maximum Likelihood Estimation (MLE), determine the optimal mean and standard deviation for a normal distribution that best fits the measured weights of a group of mice.
We have a sample of 40 packages of rice with a mean weight of 5.7 oz and a standard deviation of 0.4 oz. Find the best estimate of the population mean.
When estimating the variance, if the denominator in the sample variance is instead of , and is denoted by instead of , then it is a biased estimator.