If the sampling size n doubles, what happens to the variance of the sample mean?

Enhance your understanding of Descriptive Statistics and Probability. Study with interactive questions and detailed explanations. Prepare effectively for your test!

Multiple Choice

If the sampling size n doubles, what happens to the variance of the sample mean?

Explanation:
The main idea is that the variability of the sample mean gets smaller as you collect more data. If each observation has variance sigma^2 and you take n independent observations, the variance of their average is sigma^2/n. So when you double the sample size, you get sigma^2/(2n), which is exactly half of the original variance. In other words, the average becomes more precise with more data. The standard deviation of the sample mean also decreases, by a factor of sqrt(2).

The main idea is that the variability of the sample mean gets smaller as you collect more data. If each observation has variance sigma^2 and you take n independent observations, the variance of their average is sigma^2/n. So when you double the sample size, you get sigma^2/(2n), which is exactly half of the original variance. In other words, the average becomes more precise with more data. The standard deviation of the sample mean also decreases, by a factor of sqrt(2).

Subscribe

Get the latest from Examzify

You can unsubscribe at any time. Read our privacy policy